perf hists browser: Fix dump to show correct callchain style

The commit 8c430a34

 ("perf hists browser: Support folded
callchains") missed to update hist_browser__dump() so it always shows
graph-style callchains regardless of current setting.

To fix that, factor out callchain printing code and rename the existing
function which prints graph-style callchain.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 8c430a34

 ("perf hists browser: Support folded callchains")
Link: http://lkml.kernel.org/r/1453909257-26015-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>