[media] V4L2: Delete an unnecessary check before the function call "media_entity_put"

The media_entity_put() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/v4l2-core/v4l2-subdev.c

@@ -93,7 +93,6 @@ static int subdev_open(struct file *file)
 
 err:
 #if defined(CONFIG_MEDIA_CONTROLLER)
-	if (entity)
 	media_entity_put(entity);
 #endif
 	v4l2_fh_del(&subdev_fh->vfh);