[PATCH -next] tracing: Remove set but not used variable 'ret'

[Baokun Li <libaokun1@huawei.com>]

Fixes gcc '-Wunused-but-set-variable' warning:

kernel/trace/trace_events_hist.c: In function 'unregister_field_var_hists':
kernel/trace/trace_events_hist.c:5228:6: warning:
 variable ‘ret’ set but not used [-Wunused-but-set-variable]

It never used since introduction.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
---
 kernel/trace/trace_events_hist.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index c1abd63f1d6c..af4da32f7eab 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5225,13 +5225,12 @@ static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
 	struct trace_event_file *file;
 	unsigned int i;
 	char *cmd;
-	int ret;
 
 	for (i = 0; i < hist_data->n_field_var_hists; i++) {
 		file = hist_data->field_var_hists[i]->hist_data->event_file;
 		cmd = hist_data->field_var_hists[i]->cmd;
-		ret = event_hist_trigger_func(&trigger_hist_cmd, file,
-					      "!hist", "hist", cmd);
+		event_hist_trigger_func(&trigger_hist_cmd, file,
+					"!hist", "hist", cmd);
 	}
 }
 
-- 
2.25.4