[media] usbvision: fix locking error

If remove_pending is non-zero, then the v4l2_lock is never unlocked.

Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/usb/usbvision/usbvision-video.c

···
 	usbvision_scratch_free(usbvision);
 
 	usbvision->user--;
+	mutex_unlock(&usbvision->v4l2_lock);
 
 	if (usbvision->remove_pending) {
 		printk(KERN_INFO "%s: Final disconnect\n", __func__);
 		usbvision_release(usbvision);
 		return 0;
 	}
-	mutex_unlock(&usbvision->v4l2_lock);
 
 	PDEBUG(DBG_IO, "success");
 	return v4l2_fh_release(file);