PM / devfreq: exynos-ppmu: Fix refcount leak in of_get_devfreq_events

commit f44b799 upstream.

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
This function only calls of_node_put() in normal path,
missing it in error paths.
Add missing of_node_put() to avoid refcount leak.

Fixes: f262f28 ("PM / devfreq: event: Add devfreq_event class")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/devfreq/event/exynos-ppmu.c

@@ -514,15 +514,19 @@ static int of_get_devfreq_events(struct device_node *np,
 
 	count = of_get_child_count(events_np);
 	desc = devm_kcalloc(dev, count, sizeof(*desc), GFP_KERNEL);
-	if (!desc)
+	if (!desc) {
+		of_node_put(events_np);
 		return -ENOMEM;
+	}
 	info->num_events = count;
 
 	of_id = of_match_device(exynos_ppmu_id_match, dev);
 	if (of_id)
 		info->ppmu_type = (enum exynos_ppmu_type)of_id->data;
-	else
+	else {
+		of_node_put(events_np);
 		return -EINVAL;
+	}
 
 	j = 0;
 	for_each_child_of_node(events_np, node) {