tty: vcc: Fix error return code in vcc_probe()

Fix to return negative error code -ENOMEM from the error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/tty/vcc.c

@@ -605,6 +605,7 @@ static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 	port->index = vcc_table_add(port);
 	if (port->index == -1) {
 		pr_err("VCC: no more TTY indices left for allocation\n");
+		rv = -ENOMEM;
 		goto free_ldc;
 	}