perf tests: Add a testcase for histogram output sorting

With new output fields option, its internal implementation was changed
so add a new testcase to verify whether it breaks things.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1400480762-22852-21-git-send-email-namhyung@kernel.org


Signed-off-by: Jiri Olsa <jolsa@kernel.org>