makefs: Add SPDX-License-Identifier tags

Reviewed by: emaste
Sponsored by: The FreeBSD Foundation

usr.sbin/makefs/msdos.c

@@ -1,6 +1,8 @@
 /*	$NetBSD: msdos.c,v 1.20 2017/04/14 15:40:35 christos Exp $	*/
 
 /*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
  * All rights reserved.
  *

usr.sbin/makefs/msdos.h

@@ -1,6 +1,8 @@
 /*	$NetBSD: msdos.h,v 1.3 2015/10/16 16:40:02 christos Exp $	*/
 
 /*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
  * All rights reserved.
  *