V4L/DVB (7122): saa7134-empress: Remove back lock

videobuf functions at close() method already locks videobuf. It makes no sense
to keep the locking at empress close() method.

There is also a lock at open() method. I'm not sure if it is safe to remove the
locking there.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/saa7134/saa7134-empress.c

@@ -110,7 +110,6 @@ static int ts_release(struct inode *inode, struct file *file)
 {
 	struct saa7134_dev *dev = file->private_data;
 
-	mutex_lock(&dev->empress_tsq.vb_lock);
 	videobuf_stop(&dev->empress_tsq);
 	videobuf_mmap_free(&dev->empress_tsq);
 	dev->empress_users--;
@@ -122,7 +121,6 @@ static int ts_release(struct inode *inode, struct file *file)
 	saa_writeb(SAA7134_AUDIO_MUTE_CTRL,
 		saa_readb(SAA7134_AUDIO_MUTE_CTRL) | (1 << 6));
 
-	mutex_unlock(&dev->empress_tsq.vb_lock);
 	return 0;
 }