doc: use code-block:: none for command examples

The ``.. code-block::`` directive can specify a highlight language for
the body of the directive.  Previously the languages "none" and
"console" were the same, but we're now using "console" for creating
terminal-looking output (rather than doing images of terminal windows)
with a black background and white text.

This PR replaces unintended uses of the "console" highlighting language
with "none".

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

tools/acrn-crashlog/usercrash/README.rst

@@ -56,7 +56,7 @@ Usage
   ``core_pattern``. The content of ``core_pattern`` is configured as
   ``usercrash_c`` while booting up:
 
-.. code-block:: console
+.. code-block:: none
 
    $ echo "|/usr/bin/usercrash_c %p %e %s" > /proc/sys/kernel/core_pattern
 
@@ -67,7 +67,7 @@ event will be sent to server from client.
   specific process, including backtrace, stack, opened files, registers value,
   memory content around registers, and etc.
 
-.. code-block:: console
+.. code-block:: none
 
    $ debugger <pid>