perf tools: Handle both versions of ftrace output

The ftrace output events can have either arguments or no
arguments. The parser needs to be able to handle both.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <20091014194359.790221427@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/trace-event-parse.c

@@ -1819,7 +1819,7 @@ static int event_read_print(struct event *event)
 	if (ret < 0)
 		return -1;
 
-	return 0;
+	return ret;
 
  fail:
 	free_token(token);
@@ -3088,6 +3088,9 @@ int parse_ftrace_file(char *buf, unsigned long size)
 	if (ret < 0)
 		die("failed to read ftrace event print fmt");
 
+	/* New ftrace handles args */
+	if (ret > 0)
+		return 0;
 	/*
 	 * The arguments for ftrace files are parsed by the fields.
 	 * Set up the fields as their arguments.