perf session: Adopt resolve_callchain

This is really a generic library routine, so declutter
builtin-report.c a bit by moving it to the library.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260807780-19377-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --cc tools/perf/builtin-report.c
Simple merge

diff --cc tools/perf/util/session.c
Simple merge

diff --cc tools/perf/util/session.h
Simple merge