treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505

Based on 1 normalized pattern(s):

  gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 58 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081207.556988620@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

samples/bpf/xdp_redirect_cpu_user.c

@@ -1,4 +1,5 @@
-/* GPLv2 Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
  */
 static const char *__doc__ =
 	" XDP redirect with a CPU-map type \"BPF_MAP_TYPE_CPUMAP\"";