perf report: Generalize perf_session__fprintf_hists()

Pull it out of builtin-report - further changes will be made and it
will then be reusable in 'perf diff' as well.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260914682-29652-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/symbol.h

@@ -55,7 +55,10 @@ struct symbol_conf {
 	unsigned short	priv_size;
 	bool		try_vmlinux_path,
 			use_modules,
-			sort_by_name;
+			sort_by_name,
+			show_nr_samples,
+			use_callchain,
+			exclude_other;
 	const char	*vmlinux_name,
 			*field_sep;
 	char            *dso_list_str,