ublk_drv: fix missing error return code in ublk_add_dev()

If blk_mq_init_queue() fails, it should return error code in ublk_add_dev()

Fixes: cebbe577 ("ublk_drv: fix request queue leak")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220718042408.3132835-1-yangyingliang@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/ublk_drv.c

@@ -1169,8 +1169,10 @@ static int ublk_add_dev(struct ublk_device *ub)
 		goto out_deinit_queues;
 
 	ub->ub_queue = blk_mq_init_queue(&ub->tag_set);
-	if (IS_ERR(ub->ub_queue))
+	if (IS_ERR(ub->ub_queue)) {
+		err = PTR_ERR(ub->ub_queue);
 		goto out_cleanup_tags;
+	}
 	ub->ub_queue->queuedata = ub;
 
 	disk = ub->ub_disk = blk_mq_alloc_disk_for_queue(ub->ub_queue,