perf symbols: Preserve symbol scope when parsing /proc/kallsyms

kallsyms__parse capitalises the symbol type, so every symbol is marked
global. Remove this and fix symbol_type__is_a to handle both local and
global symbols.

Cc: Eric B Munson <emunson@mgebm.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110824065243.077125989@samba.org


Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>