net: wan: replace comparison to NULL with "!card"

According to the chackpatch.pl, comparison to NULL could
be written "!card".
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wan/wanxl.c

@@ -600,7 +600,7 @@ static int wanxl_pci_init_one(struct pci_dev *pdev,
 	}
 
 	card = kzalloc(struct_size(card, ports, ports), GFP_KERNEL);
-	if (card == NULL) {
+	if (!card) {
 		pci_release_regions(pdev);
 		pci_disable_device(pdev);
 		return -ENOBUFS;
@@ -612,7 +612,7 @@ static int wanxl_pci_init_one(struct pci_dev *pdev,
 	card->status = dma_alloc_coherent(&pdev->dev,
 					  sizeof(struct card_status),
 					  &card->status_address, GFP_KERNEL);
-	if (card->status == NULL) {
+	if (!card->status) {
 		wanxl_pci_remove_one(pdev);
 		return -ENOBUFS;
 	}