tools lib traceevent: Get rid of die() from pevent_register_event_handler

tools lib traceevent: Get rid of die() from pevent_register_event_handler

If memory allocation for handler fails, return gracefully instead of
calling die().  Note that casts to void * are needed because gcc
complained about discarding 'const' qualifier during implicit argument
cast.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1346986187-5170-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>