[media] v4l: vsp1: Fix mutex double lock at streamon time

A mutex_lock() was left when the driver was converted to use the vb2
ioctl helpers, resulting in a deadlock at streamon time. Fix it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/vsp1/vsp1_video.c

@@ -839,8 +839,6 @@ vsp1_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
 	struct vsp1_pipeline *pipe;
 	int ret;
 
-	mutex_lock(&video->lock);
-
 	if (video->queue.owner && video->queue.owner != file->private_data)
 		return -EBUSY;