RDMA/nes: Fix error return code

Set the return variable to an error code as done elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}

// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

drivers/infiniband/hw/nes/nes.c

@@ -675,8 +675,11 @@ static int nes_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
 	INIT_DELAYED_WORK(&nesdev->work, nes_recheck_link_status);
 
 	/* Initialize network devices */
-	if ((netdev = nes_netdev_init(nesdev, mmio_regs)) == NULL)
+	netdev = nes_netdev_init(nesdev, mmio_regs);
+	if (netdev == NULL) {
+		ret = -ENOMEM;
 		goto bail7;
+	}
 
 	/* Register network device */
 	ret = register_netdev(netdev);