confile: cleanup clr_config_net_type()

src/lxc/confile.c

@@ -4837,7 +4837,7 @@ static int clr_config_net_type(const char *key, struct lxc_conf *lxc_conf,
 	struct lxc_netdev *netdev = data;
 
 	if (!netdev)
-		return -1;
+		return ret_errno(EINVAL);
 
 	netdev->type = -1;