perf hists: Make hists__fprintf_headers function global

Will be used from external places in the upcoming c2c patch series.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-10-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index ecc4c0c..9928fed 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -489,5 +489,6 @@
 int __hpp__slsmg_color_printf(struct perf_hpp *hpp, const char *fmt, ...);
 int __hist_entry__snprintf(struct hist_entry *he, struct perf_hpp *hpp,
 			   struct perf_hpp_list *hpp_list);
+int hists__fprintf_headers(struct hists *hists, FILE *fp);
 
 #endif	/* __PERF_HIST_H */