perf tools: Handle PERF_RECORD_HEADER_EVENT_TYPE properly

We removed event types from data file in following commits:

6065210 perf tools: Remove event types framework completely
44b3c57 perf tools: Remove event types from perf data file

We no longer need this information, because we can get it directly from
tracepoints.

But we still need to handle PERF_RECORD_HEADER_EVENT_TYPE event for the
sake of old perf data files created in pipe mode like:

$ perf.3.4 record -o - foo >perf.data
$ perf.312 report -i - < perf.data

Reported-by: Stephane Eranian <[e-mail]>
Signed-off-by: Jiri Olsa <[e-mail]>
Cc: Corey Ashford <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/session.c

···
 		if (err == 0)
 			perf_session__set_id_hdr_size(session);
 		return err;
+	case PERF_RECORD_HEADER_EVENT_TYPE:
+		/*
+		 * Depreceated, but we need to handle it for sake
+		 * of old data files create in pipe mode.
+		 */
+		return 0;
 	case PERF_RECORD_HEADER_TRACING_DATA:
 		/* setup for reading amidst mmap */
 		lseek(fd, file_offset, SEEK_SET);