Remove useless return statements.

module/VuFind/src/VuFind/Controller/ShibbolethLogoutNotificationController.php

@@ -109,7 +109,6 @@ class ShibbolethLogoutNotificationController extends AbstractBase
         $sessionManager = $this->serviceLocator->get('VuFind\SessionManager');
         $handler = $sessionManager->getSaveHandler();
         $handler->destroy($row['session_id']);
-        return;
     }
 
     /**

module/VuFind/tests/unit-tests/src/VuFindTest/ILS/Driver/MultiBackendTest.php

@@ -2466,7 +2466,6 @@ class DummyILS extends \VuFind\ILS\Driver\AbstractBase
      */
     public function init()
     {
-        return;
     }
 
     /**