perf tools: Remove string.h, unistd.h and sys/stat.h from util.h

Not needed in this header, added to the places that need FILE,
putchar(), access() and a few other prototypes.

Link: http://lkml.kernel.org/n/tip-xxtdsl6nsna82j7puwbdjqhs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-version.c b/tools/perf/builtin-version.c
index b9a095b..d251494 100644
--- a/tools/perf/builtin-version.c
+++ b/tools/perf/builtin-version.c
@@ -1,6 +1,7 @@
-#include "util/util.h"
 #include "builtin.h"
 #include "perf.h"
+#include <linux/compiler.h>
+#include <stdio.h>
 
 int cmd_version(int argc __maybe_unused, const char **argv __maybe_unused)
 {