treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433

Based on 1 normalized pattern(s):

  released under the gpl v2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 2 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.749096322@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/perf/builtin-ftrace.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * builtin-ftrace.c
  *
  * Copyright (c) 2013  LG Electronics,  Namhyung Kim <namhyung@kernel.org>
- *
- * Released under the GPL v2.
  */
 
 #include "builtin.h"

tools/perf/util/target.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Helper functions for handling target threads/cpus
  *
  * Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com>
- *
- * Released under the GPL v2.
  */
 
 #include "target.h"