Revert "merged branch povilas/issue_6101 (PR symfony#6708)"

This reverts commit b2bcbbb, reversing
changes made to c5fcf0d.

Author: fabpot

src/Symfony/Component/HttpFoundation/BinaryFileResponse.php

@@ -22,7 +22,6 @@
  * @author Igor Wiedler <igor@wiedler.ch>
  * @author Jordan Alliot <jordan.alliot@gmail.com>
  * @author Sergey Linnik <linniksa@gmail.com>
- * @author Povilas Skruibis <puovils@gmail.com>
  */
 class BinaryFileResponse extends Response
 {
@@ -124,23 +123,11 @@ public function setAutoLastModified()
      */
     public function setAutoEtag()
     {
-        $this->setEtag($this->calculateFileHash($this->file->getPathname()));
+        $this->setEtag(sha1_file($this->file->getPathname()));
 
         return $this;
     }
 
-    /**
-     * Calculate file hash
-     *
-     * @param string $filename The path to the file
-     * 
-     * @return string
-     */
-    protected function calculateFileHash($filename)
-    {
-        return sha1_file($filename);
-    }
-
     /**
      * Sets the Content-Disposition header with the given filename.
      *