media: imx: Clean capture unregister

No locking is needed to call video_unregister_device(). Drop it.

Also, drop the superfluous video_is_registered() call, which is
done by video_unregister_device(), and re-order media_entity_cleanup()
and video_unregister_device() calls.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/imx/imx-media-capture.c

@@ -816,14 +816,8 @@ void imx_media_capture_device_unregister(struct imx_media_video_dev *vdev)
 	struct capture_priv *priv = to_capture_priv(vdev);
 	struct video_device *vfd = priv->vdev.vfd;
 
-	mutex_lock(&priv->mutex);
-
-	if (video_is_registered(vfd)) {
-		video_unregister_device(vfd);
 	media_entity_cleanup(&vfd->entity);
-	}
-
-	mutex_unlock(&priv->mutex);
+	video_unregister_device(vfd);
 }
 EXPORT_SYMBOL_GPL(imx_media_capture_device_unregister);