perf: Make common SAMPLE_EVENT parser

Currently, sample event data is parsed for each commands, and it
is assuming that the data is not including other data. (E.g.
timechart, trace, etc. can't parse the event if it has
PERF_SAMPLE_CALLCHAIN)

So, even if we record the superset data for multiple commands at
a time, commands can't parse. etc.

To fix it, this makes common sample event parser, and use it to
parse sample event correctly. (PERF_SAMPLE_READ is unsupported
for now though, it seems to be not using.)

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <87hbs48imv.fsf@devron.myhome.or.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>