nvme-pci: always return an ERR_PTR from nvme_pci_alloc_dev

Don't mix NULL and ERR_PTR returns.

Fixes: 2e87570b ("nvme-pci: factor out a nvme_pci_alloc_dev helper")
Signed-off-by: NIrvin Cote <irvin.cote@insa-lyon.fr>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -2964,7 +2964,7 @@ static struct nvme_dev *nvme_pci_alloc_dev(struct pci_dev *pdev,
 
 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
 	if (!dev)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	INIT_WORK(&dev->ctrl.reset_work, nvme_reset_work);
 	mutex_init(&dev->shutdown_lock);
 
@@ -3029,8 +3029,8 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	int result = -ENOMEM;
 
 	dev = nvme_pci_alloc_dev(pdev, id);
-	if (!dev)
-		return -ENOMEM;
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
 
 	result = nvme_dev_map(dev);
 	if (result)