Clean Up Magento/ImportExport/Controller/Adminhtml/History/Download

[dmanners]

Preconditions (*)

1. 2.3-develop
2. phpstan installed

Steps to reproduce (*)

1. ./vendor/bin/phpstan analyse -l 0 app/code/Magento/ImportExport/Controller/Adminhtml/History/Download.php

Expected result (*)

1. No errors

Actual result (*)

 1/1 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%

 ------ ----------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Line   Download.php
 ------ ----------------------------------------------------------------------------------------------------------------------------------------------------------------------
  31     Access to an undefined property Magento\ImportExport\Controller\Adminhtml\History\Download::$fileFactory.
  54     Access to an undefined property Magento\ImportExport\Controller\Adminhtml\History\Download::$fileFactory.
 ------ ----------------------------------------------------------------------------------------------------------------------------------------------------------------------


 [ERROR] Found 2 errors