tools lib traceevent: Fix a possible memory leak

If event_read_fields failed in the middle, each member of
struct format_field should be freed also.

Cc: Borislav Petkov <bp@alien8.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337740619-27925-11-git-send-email-namhyung.kim@lge.com
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.c

@@ -1434,8 +1434,11 @@ static int event_read_fields(struct event_format *event, struct format_field **f
 fail:
 	free_token(token);
 fail_expect:
-	if (field)
+	if (field) {
+		free(field->type);
+		free(field->name);
 		free(field);
+	}
 	return -1;
 }