esp_event: fix minor memory leak when overwriting alredy registered handler

components/esp_event/esp_event.c

@@ -164,6 +164,7 @@ static esp_err_t handler_instances_add(esp_event_handler_instances_t* handlers,
             if (handler == it->handler) {
                 it->arg = handler_arg;
                 ESP_LOGW(TAG, "handler already registered, overwriting");
+                free(handler_instance);
                 return ESP_OK;
             }
             last = it;