SUNRPC: Fix an error code in gss_alloc_msg()

If kstrdup_const() then this function returns zero (success) but it
should return -ENOMEM.

Fixes: ac83228a ("SUNRPC: Use namespace of listening daemon in the client AUTH_GSS upcall")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/auth_gss/auth_gss.c

@@ -553,9 +553,11 @@ gss_alloc_msg(struct gss_auth *gss_auth,
 	gss_msg->auth = gss_auth;
 	if (service_name) {
 		gss_msg->service_name = kstrdup_const(service_name, GFP_NOFS);
-		if (!gss_msg->service_name)
+		if (!gss_msg->service_name) {
+			err = -ENOMEM;
 			goto err_put_pipe_version;
 		}
+	}
 	return gss_msg;
 err_put_pipe_version:
 	put_pipe_version(gss_auth->net);