libtraceevent: Fix parsing of event %o and %X argument types

Add missing "%o" and "%X". Ext4 events use "%o" for printing i_mode.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Link: http://lore.kernel.org/lkml/157338066113.6548.11461421296091086041.stgit@buzz


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>