s390/ism: fix error return code in ism_probe()

Fix to return negative error code -ENOMEM from the smcd_alloc_dev()
error handling case instead of 0, as done elsewhere in this function.

Fixes: 684b89bc ("s390/ism: add device driver for internal shared memory")
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/s390/net/ism_drv.c

@@ -521,8 +521,10 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	ism->smcd = smcd_alloc_dev(&pdev->dev, dev_name(&pdev->dev), &ism_ops,
 				   ISM_NR_DMBS);
-	if (!ism->smcd)
+	if (!ism->smcd) {
+		ret = -ENOMEM;
 		goto err_resource;
+	}
 
 	ism->smcd->priv = ism;
 	ret = ism_dev_init(ism);