perf hists browser: Convert hpp helpers to a function

perf hists browser: Convert hpp helpers to a function

The hpp helpers do same job for each field so it was implemented as
macro in order to access those fields easily.  But it gets cumbersome
to maintain a large function in a macro as the function grows. Factor
it out to a function with a little helper macro to access field.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1358845787-1350-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>