MAGETWO-62807: Case information block on order details page in admin panel

- refactoring

Author: iivashchenko

app/code/Magento/Sales/view/adminhtml/templates/order/view/additional_info.phtml

@@ -3,6 +3,6 @@
  * Copyright © 2013-2017 Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-?>
-<?php /** $block \Magento\Sales\Block\Adminhtml\Order\View\AdditionalInfo */?>
-<?php echo $block->getChildHtml()?>
+
+/** $block \Magento\Sales\Block\Adminhtml\Order\View\AdditionalInfo */
+echo $block->getChildHtml();