ENGCOM-1544: [Backport] Corrected param in docblock #15183

 - Merge Pull Request #15183 from rogyar/magento2:2.1-urlinterface-docblock-fix
 - Merged commits:
   1. d6248a2

Author: magento-engcom-team

app/code/Magento/OfflineShipping/Block/Adminhtml/Form/Field/Export.php

@@ -21,7 +21,7 @@ class Export extends \Magento\Framework\Data\Form\Element\AbstractElement
      * @param \Magento\Framework\Data\Form\Element\Factory $factoryElement
      * @param \Magento\Framework\Data\Form\Element\CollectionFactory $factoryCollection
      * @param \Magento\Framework\Escaper $escaper
-     * @param \Magento\Backend\Helper\Data $helper
+     * @param \Magento\Backend\Model\UrlInterface $backendUrl
      * @param array $data
      */
     public function __construct(