perf bench futex: Add missing compiler.h header

Since these files use __maybe_unused, and that is defined in
linux/compiler.h, include it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1llbf59ut6xon6ti88jm0n9j@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bench/futex-hash.c

@@ -14,6 +14,7 @@
 #include <errno.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <sys/time.h>
 

tools/perf/bench/futex-lock-pi.c

@@ -8,6 +8,7 @@
 #include <signal.h>
 #include "../util/stat.h"
 #include <subcmd/parse-options.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <errno.h>
 #include "bench.h"

tools/perf/bench/futex-requeue.c

@@ -14,6 +14,7 @@
 #include <signal.h>
 #include "../util/stat.h"
 #include <subcmd/parse-options.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <errno.h>
 #include "bench.h"

tools/perf/bench/futex-wake-parallel.c

@@ -13,6 +13,7 @@
 #include <signal.h>
 #include "../util/stat.h"
 #include <subcmd/parse-options.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <errno.h>
 #include "bench.h"

tools/perf/bench/futex-wake.c

@@ -14,6 +14,7 @@
 #include <signal.h>
 #include "../util/stat.h"
 #include <subcmd/parse-options.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <errno.h>
 #include "bench.h"