Merge pull request #47900 from yiqinguo/yiqinguo_add_type_judgment

Automatic merge from submit-queue

Add type conversion judgment

If do not type conversion judgment, there may be panic.

**Release note**:
```release-note
NONE
```

pkg/kubelet/dockershim/docker_service.go

@@ -455,10 +455,13 @@ func (ds *dockerService) getDockerVersionFromCache() (*dockertypes.Version, erro
 	// We only store on key in the cache.
 	const dummyKey = "version"
 	value, err := ds.versionCache.Get(dummyKey)
-	dv := value.(*dockertypes.Version)
 	if err != nil {
 		return nil, err
 	}
+	dv, ok := value.(*dockertypes.Version)
+	if !ok {
+		return nil, fmt.Errorf("Converted to *dockertype.Version error")
+	}
 	return dv, nil
 }