NFC: NCI: Fix NULL pointer dereference

The check should be for setup function pointer.

This patch fixes NULL pointer dereference issue for NCI
based NFC driver which doesn't define setup handler.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

net/nfc/nci/core.c

@@ -301,7 +301,7 @@ static int nci_open_device(struct nci_dev *ndev)
 	rc = __nci_request(ndev, nci_reset_req, 0,
 			   msecs_to_jiffies(NCI_RESET_TIMEOUT));
 
-	if (ndev->ops->setup(ndev))
+	if (ndev->ops->setup)
 		ndev->ops->setup(ndev);
 
 	if (!rc) {