perf top: Move UI initialization ahead of sort setup

The ui initialization changes hpp format callbacks, based on the used
browser. Thus we need this init being processed before setup_sorting.

Replica of a patch by Jiri for 'perf report'.

Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1453109064-1026-9-git-send-email-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>