perf tools: Create maps for modules when processing kallsyms

So that we get kallsyms processing closer to vmlinux + modules
symtabs processing.

One change in behaviour is that since when one specifies --vmlinux
-m should be used to ask for modules, so it is now for kallsyms as
well.

Also continue if one manages to load the vmlinux data but module
processing fails, so that at least some analisys can be done with
part of the needed symbols.

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>