V4L/DVB (10270): saa7146: fix unbalanced mutex_lock/unlock

The default case of the switch didn't unlock the mutex.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/common/saa7146_video.c b/drivers/media/common/saa7146_video.c
index 6098b62..47fee05 100644
--- a/drivers/media/common/saa7146_video.c
+++ b/drivers/media/common/saa7146_video.c
@@ -576,6 +576,7 @@
 		vv->vflip = c->value;
 		break;
 	default: {
+		mutex_unlock(&dev->lock);
 		return -EINVAL;
 	}
 	}