media: au0828: fix unbalanced lock/unlock in au0828_usb_probe

Call mutex_unlock and free dev on failure.
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/au0828/au0828-core.c

@@ -628,6 +628,8 @@ static int au0828_usb_probe(struct usb_interface *interface,
 	if (retval) {
 		pr_err("%s() au0282_dev_register failed to register on V4L2\n",
 			__func__);
+		mutex_unlock(&dev->lock);
+		kfree(dev);
 		goto done;
 	}