fix(wifi): fixed the vendor ie length issue

components/esp_wifi/include/esp_wifi.h

@@ -1000,6 +1000,9 @@ typedef void (*esp_vendor_ie_cb_t) (void *ctx, wifi_vendor_ie_type_t type, const
   * @param     vnd_ie Pointer to vendor specific element data. First 6 bytes should be a header with fields matching vendor_ie_data_t.
   *            If enable is false, this argument is ignored and can be NULL. Data does not need to remain valid after the function returns.
   *
+  * @attention If user set the same vendor ie twice, the second set will fail and return ESP_ERR_INVALID_ARG.
+  *            Please clear the vendor ie before setting again.
+  *
   * @return
   *    - ESP_OK: succeed
   *    - ESP_ERR_WIFI_NOT_INIT: WiFi is not initialized by esp_wifi_init()