perf report: Do map lookups in resolve_callchain()

perf report: Do map lookups in resolve_callchain()

Bug introduced in 157160c4a00f660182d3f3e88d0a9bc3ae9a12f3,
making the initial map be used for all IPs, so that symbols
outside this initial map would either be erroneously resolved or
not resolve at all.

Reported-by: Ingo Molnar <mingo@elte.hu>
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: <1258909162-28496-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>