IB/core: fix an error code in ib_core_init()

We should return the error code if ib_add_ibnl_clients() fails.  The
current code returns success.

Fixes: 735c631ae99d ('IB/core: Register SA ibnl client during ib_core initialization')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/device.c

@@ -1024,7 +1024,8 @@ static int __init ib_core_init(void)
 		goto err_mad;
 	}
 
-	if (ib_add_ibnl_clients()) {
+	ret = ib_add_ibnl_clients();
+	if (ret) {
 		pr_warn("Couldn't register ibnl clients\n");
 		goto err_sa;
 	}