Merge branch 'bugfix/fix_memory_leak_in_ws_server_example_v5.1' into …

…'release/v5.1'

example: Fix memory leak in ws_echo_server when httpd_queue_work failed (backport v5.1)

See merge request espressif/esp-idf!23955

examples/protocols/http_server/ws_echo_server/main/ws_echo_server.c

@@ -55,9 +55,16 @@ static void ws_async_send(void *arg)
 static esp_err_t trigger_async_send(httpd_handle_t handle, httpd_req_t *req)
 {
     struct async_resp_arg *resp_arg = malloc(sizeof(struct async_resp_arg));
+    if (resp_arg == NULL) {
+        return ESP_ERR_NO_MEM;
+    }
     resp_arg->hd = req->handle;
     resp_arg->fd = httpd_req_to_sockfd(req);
-    return httpd_queue_work(handle, ws_async_send, resp_arg);
+    esp_err_t ret = httpd_queue_work(handle, ws_async_send, resp_arg);
+    if (ret != ESP_OK) {
+        free(resp_arg);
+    }
+    return ret;
 }
 
 /*