compile fix

src/firejail/landlock.c

@@ -1,3 +1,24 @@
+/*
+ * Copyright (C) 2014-2022 Firejail Authors
+ *
+ * This file is part of firejail project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifdef HAVE_LANDLOCK
 #define _GNU_SOURCE
 #include <stdio.h>
 #include <stddef.h>
@@ -77,3 +98,4 @@ int add_execute_rule_by_path(int rset_fd,char *allowed_path) {
 	close(allowed_fd);
 	return result;
 }
+#endif