Phriction - fix "unknown policy" on document create

Summary: when creating new documents the policy object wasn't being initialized properly. update the code to use the new handy initializeNewDocument method. Fixes T6527.

Test Plan: viewed a doc at /w/asdsadsadsdas/ and saw the correct policy setting

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T6527

Differential Revision: https://secure.phabricator.com/D10837

Author: bobtrahan

src/applications/phriction/controller/PhrictionDocumentController.php

@@ -38,7 +38,7 @@ public function processRequest() {
 
     if (!$document) {
 
-      $document = new PhrictionDocument();
+      $document = PhrictionDocument::initializeNewDocument($user, $slug);
 
       $create_uri = '/phriction/edit/?slug='.$slug;