[PATCH] tracing: Remove unnecessary var_ref destroy in track_data_destroy()

[Tom Zanussi]

Commit 656fe2ba85e8 (tracing: Use hist trigger's var_ref array to
destroy var_refs) centralized the destruction of all the var_refs
in one place so that other code didn't have to do it.

The track_data_destroy() added later ignored that and also destroyed
the track_data var_ref, causing a double-free error flagged by KASAN.

So remove the track_data_destroy() destroy_hist_field() call for that
var_ref.

Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
---
 kernel/trace/trace_events_hist.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ca46339..795aa20 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3713,7 +3713,6 @@ static void track_data_destroy(struct hist_trigger_data *hist_data,
 	struct trace_event_file *file = hist_data->event_file;
 
 	destroy_hist_field(data->track_data.track_var, 0);
-	destroy_hist_field(data->track_data.var_ref, 0);
 
 	if (data->action == ACTION_SNAPSHOT) {
 		struct track_data *track_data;
-- 
2.7.4