partners/HuggingFacePipeline[stream]: Change to use pipeline instead of pipeline.model.generate in stream() (#26531)

## Description

I encountered an error while using the` gemma-2-2b-it model` with the
`HuggingFacePipeline` class and have implemented a fix to resolve this
issue.

### What is Problem

```python
model_id="google/gemma-2-2b-it"


gemma_2_model = AutoModelForCausalLM.from_pretrained(model_id)
gemma_2_tokenizer = AutoTokenizer.from_pretrained(model_id)

gen = pipeline( 
    task='text-generation',
    model=gemma_2_model,
    tokenizer=gemma_2_tokenizer,
    max_new_tokens=1024,
    device=0 if torch.cuda.is_available() else -1,
    temperature=.5,
    top_p=0.7,
    repetition_penalty=1.1,
    do_sample=True,
    )

llm = HuggingFacePipeline(pipeline=gen)

for chunk in llm.stream("Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World."):
    print(chunk, end="", flush=True)
```

This code outputs the following error message:

```
/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py:1258: UserWarning: Using the model-agnostic default `max_length` (=20) to control the generation length. We recommend setting `max_new_tokens` to control the maximum length of the generation.
  warnings.warn(
Exception in thread Thread-19 (generate):
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/local/lib/python3.10/dist-packages/torch/utils/_contextlib.py", line 116, in decorate_context
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 1874, in generate
    self._validate_generated_length(generation_config, input_ids_length, has_default_max_length)
  File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 1266, in _validate_generated_length
    raise ValueError(
ValueError: Input length of input_ids is 31, but `max_length` is set to 20. This can lead to unexpected behavior. You should consider increasing `max_length` or, better yet, setting `max_new_tokens`.
```

In addition, the following error occurs when the number of tokens is
reduced.

```python
for chunk in llm.stream("Hello World"):
    print(chunk, end="", flush=True)
```

```
/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py:1258: UserWarning: Using the model-agnostic default `max_length` (=20) to control the generation length. We recommend setting `max_new_tokens` to control the maximum length of the generation.
  warnings.warn(
/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py:1885: UserWarning: You are calling .generate() with the `input_ids` being on a device type different than your model's device. `input_ids` is on cpu, whereas the model is on cuda. You may experience unexpected behaviors or slower generation. Please make sure that you have put `input_ids` to the correct device by calling for example input_ids = input_ids.to('cuda') before running `.generate()`.
  warnings.warn(
Exception in thread Thread-20 (generate):
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/local/lib/python3.10/dist-packages/torch/utils/_contextlib.py", line 116, in decorate_context
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 2024, in generate
    result = self._sample(
  File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 2982, in _sample
    outputs = self(**model_inputs, return_dict=True)
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1553, in _wrapped_call_impl
    return self._call_impl(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1562, in _call_impl
    return forward_call(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/transformers/models/gemma2/modeling_gemma2.py", line 994, in forward
    outputs = self.model(
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1553, in _wrapped_call_impl
    return self._call_impl(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1562, in _call_impl
    return forward_call(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/transformers/models/gemma2/modeling_gemma2.py", line 803, in forward
    inputs_embeds = self.embed_tokens(input_ids)
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1553, in _wrapped_call_impl
    return self._call_impl(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1562, in _call_impl
    return forward_call(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/sparse.py", line 164, in forward
    return F.embedding(
  File "/usr/local/lib/python3.10/dist-packages/torch/nn/functional.py", line 2267, in embedding
    return torch.embedding(weight, input, padding_idx, scale_grad_by_freq, sparse)
RuntimeError: Expected all tensors to be on the same device, but found at least two devices, cuda:0 and cpu! (when checking argument for argument index in method wrapper_CUDA__index_select)
```

On the other hand, in the case of invoke, the output is normal:

```
llm.invoke("Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World.")
```
```
'Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World. Hello World.\n\nThis is a simple program that prints the phrase "Hello World" to the console. \n\n**Here\'s how it works:**\n\n* **`print("Hello World")`**: This line of code uses the `print()` function, which is a built-in function in most programming languages (like Python). The `print()` function takes whatever you put inside its parentheses and displays it on the screen.\n* **`"Hello World"`**:  The text within the double quotes (`"`) is called a string. It represents the message we want to print.\n\n\nLet me know if you\'d like to explore other programming concepts or see more examples! \n'
```

### Problem Analysis

- Apparently, I put kwargs in while generating pipelines and it applied
to `invoke()`, but it's not applied in the `stream()`.
- When using the stream, `inputs = self.pipeline.tokenizer (prompt,
return_tensors = "pt")` enters cpu.
  - This can crash when the model is in gpu.

### Solution

Just use `self.pipeline` instead of `self.pipeline.model.generate`.

- **Original Code**

```python
stopping_criteria = StoppingCriteriaList([StopOnTokens()])

inputs = self.pipeline.tokenizer(prompt, return_tensors="pt")
streamer = TextIteratorStreamer(
    self.pipeline.tokenizer,
    timeout=60.0,
    skip_prompt=skip_prompt,
    skip_special_tokens=True,
)
generation_kwargs = dict(
    inputs,
    streamer=streamer,
    stopping_criteria=stopping_criteria,
    **pipeline_kwargs,
)
t1 = Thread(target=self.pipeline.model.generate, kwargs=generation_kwargs)
t1.start()
```

- **Updated Code**

```python
stopping_criteria = StoppingCriteriaList([StopOnTokens()])

streamer = TextIteratorStreamer(
    self.pipeline.tokenizer,
    timeout=60.0,
    skip_prompt=skip_prompt,
    skip_special_tokens=True,
)
generation_kwargs = dict(
    text_inputs= prompt,
    streamer=streamer,
    stopping_criteria=stopping_criteria,
    **pipeline_kwargs,
)
t1 = Thread(target=self.pipeline, kwargs=generation_kwargs)
t1.start()
```

By using the `pipeline` directly, the `kwargs` of the pipeline are
applied, and there is no need to consider the `device` of the `tensor`
made with the `tokenizer`.

> According to the change to use `pipeline`, it was modified to put
`text_inputs=prompts` directly into `generation_kwargs`.

## Issue

None

## Dependencies

None

## Twitter handle

None

---------

Co-authored-by: Vadym Barda <vadym@langchain.dev>

libs/partners/huggingface/langchain_huggingface/llms/huggingface_pipeline.py

@@ -349,7 +349,6 @@ class HuggingFacePipeline(BaseLLM):
 
         stopping_criteria = StoppingCriteriaList([StopOnTokens()])
 
-        inputs = self.pipeline.tokenizer(prompt, return_tensors="pt")
         streamer = TextIteratorStreamer(
             self.pipeline.tokenizer,
             timeout=60.0,
@@ -357,12 +356,12 @@ class HuggingFacePipeline(BaseLLM):
             skip_special_tokens=True,
         )
         generation_kwargs = dict(
-            inputs,
+            text_inputs=prompt,
             streamer=streamer,
             stopping_criteria=stopping_criteria,
             **pipeline_kwargs,
         )
-        t1 = Thread(target=self.pipeline.model.generate, kwargs=generation_kwargs)
+        t1 = Thread(target=self.pipeline, kwargs=generation_kwargs)
         t1.start()
 
         for char in streamer: