Use __CLASS__ instead of hard-coding class names

Summary: Use `__CLASS__` instead of hard-coding class names. Depends on D12605.

Test Plan: Eyeball it.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: hach-que, Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D12806

src/applications/cache/PhabricatorCaches.php

@@ -270,7 +270,7 @@ final class PhabricatorCaches {
   }
 
   private static function addNamespaceToCaches(array $caches) {
-    $namespace = PhabricatorCaches::getNamespace();
+    $namespace = self::getNamespace();
     if (!$namespace) {
       return $caches;
     }