Add missing SPDX headers

All headers and source in iproute2 should be using SPDX license info.
Add a couple that were missed, and take off boilerplate.

Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

include/bpf_util.h

@@ -1,11 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * bpf_util.h	BPF common code
  *
- *		This program is free software; you can distribute 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.
- *
  * Authors:	Daniel Borkmann <daniel@iogearbox.net>
  *		Jiri Pirko <jiri@resnulli.us>
  */

include/cg_map.h

@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __CG_MAP_H__
 #define __CG_MAP_H__
 

include/json_print.h

@@ -1,10 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
- * json_print.h		"print regular or json output, based on json_writer".
- *
- *             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.
+ * json_print.h		print regular or json output, based on json_writer.
  *
  * Authors:    Julien Fortin, <julien@cumulusnetworks.com>
  */