perf script: Process event update events

Andreas reported following command produces no output:

  # cat test.py
  #!/usr/bin/env python

  def stat__krava(cpu, thread, time, val, ena, run):
      print "event %s cpu %d, thread %d, time %d, val %d, ena %d, run %d" % \
            ("krava", cpu, thread, time, val, ena, run)
  # perf stat -a -I 1000 -e cycles,"cpu/config=0x6530160,name=krava/" record | perf script -s test.py
  ^C
  #

The reason is that 'perf script' does not process event update events and
will never get the event name update thus the python callback is never
called.

The fix is just to add already existing callback we use in 'perf stat
report'.

Committer note:

After the patch:

  # perf stat -a -I 1000 -e cycles,"cpu/config=0x6530160,name=krava/" record | perf script -s test.py
  event krava cpu -1, thread -1, time 1000239179, val 1789051, ena 4000690920, run 4000690920
  event krava cpu -1, thread -1, time 2000479061, val 2391338, ena 4000879596, run 4000879596
  event krava cpu -1, thread -1, time 3000740802, val 1939121, ena 4000977209, run 4000977209
  event krava cpu -1, thread -1, time 4001006730, val 2356115, ena 4001000489, run 4001000489
  ^C
  #

Reported-by: Andreas Hollmann <hollmann@in.tum.de>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1460013073-18444-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-script.c

@@ -1961,6 +1961,7 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
 			.exit		 = perf_event__process_exit,
 			.fork		 = perf_event__process_fork,
 			.attr		 = process_attr,
+			.event_update   = perf_event__process_event_update,
 			.tracing_data	 = perf_event__process_tracing_data,
 			.build_id	 = perf_event__process_build_id,
 			.id_index	 = perf_event__process_id_index,