perf report: Use kernel_maps__find_symbol as fallback to find vdsos, etc

In resolve_symbol, as we're moving to breaking the kernel symbols
list per address ranges, i.e. kernel linking sections, so that we
don't have a big kernel_map that in its range covers what is in the
modules.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>