ENGCOM-2572: [Backport] Credit memo email template file: fixing incorrect object type error #17224

 - Merge Pull Request #17224 from gelanivishal/magento2:2.1-develop-PR-port-16438
 - Merged commits:
   1. 9c4dfbd

Author: magento-engcom-team

app/code/Magento/Sales/view/frontend/templates/email/items/creditmemo/default.phtml

@@ -31,6 +31,6 @@
     </td>
     <td class="item-qty"><?= /* @escapeNotVerified */  $_item->getQty() * 1 ?></td>
     <td class="item-price">
-        <?= /* @escapeNotVerified */  $block->getItemPrice($_item); ?>
+        <?= /* @escapeNotVerified */  $block->getItemPrice($_item->getOrderItem()) ?>
     </td>
 </tr>