perf top: Fix userspace sample addr map offset

perf top: Fix userspace sample addr map offset

The 'perf top' tool came from the kernel where we had each DSO (vmlinux,
modules) loaded just once at a time.

But userspace may have DSOs loaded in multiple addresses (shared
libraries), requiring that we use the just resolved map instead of the
first one found.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ag53wz0yllpgers0n2w7hchp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>