tools lib traceevent: Fix error path on pevent_parse_event

If __pevent_parse_format() succeeded but add_event() failed, 'ret' didn't
have a proper error code.  Set it to PEVENT_ERRNO__MEM_ALLOC_FAILED.

In addition, at that point 'event' also has fields and format
information and they all need to be freed.  Call pevent_free_format() to
handle it.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1348575919-4954-1-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.c

@@ -5044,8 +5044,10 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
 	/* Add pevent to event so that it can be referenced */
 	event->pevent = pevent;
 
-	if (add_event(pevent, event))
+	if (add_event(pevent, event)) {
+		ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
 		goto event_add_failed;
+	}
 
 #define PRINT_ARGS 0
 	if (PRINT_ARGS && event->print_fmt.args)
@@ -5054,9 +5056,7 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
 	return 0;
 
 event_add_failed:
-	free(event->system);
-	free(event->name);
-	free(event);
+	pevent_free_format(event);
 	return ret;
 }