umem: fix error return code in mm_pci_probe()

Fix to return negative error code -ENOMEM from the blk_alloc_queue()
and dma_alloc_coherent() error handling cases instead of 0, as done
elsewhere in this function.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210308123501.2573816-1-weiyongjun1@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/umem.c

@@ -877,6 +877,7 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (card->mm_pages[0].desc == NULL ||
 	    card->mm_pages[1].desc == NULL) {
 		dev_printk(KERN_ERR, &card->dev->dev, "alloc failed\n");
+		ret = -ENOMEM;
 		goto failed_alloc;
 	}
 	reset_page(&card->mm_pages[0]);
@@ -888,8 +889,10 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	spin_lock_init(&card->lock);
 
 	card->queue = blk_alloc_queue(NUMA_NO_NODE);
-	if (!card->queue)
+	if (!card->queue) {
+		ret = -ENOMEM;
 		goto failed_alloc;
+	}
 
 	tasklet_init(&card->tasklet, process_page, (unsigned long)card);