media: uvcvideo: Avoid variable shadowing in uvc_ctrl_cleanup_fh

This avoids a variable loop shadowing occurring between the local loop
iterating through the uvc_entity's controls and the global one going
through the pending async controls of the file handle.

Fixes: 10acb910 ("media: uvcvideo: Increase/decrease the PM counter per IOCTL")
Cc: stable@vger.kernel.org
Signed-off-by: Desnes Nunes <desnesn@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>