fix RegisterListenersPass test

With #12088 being merged, the test needs to be adapted to reflect the
2.5 specific changes.

src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php

@@ -74,7 +74,7 @@ public function testValidEventSubscriber()
 
         $builder = $this->getMock(
             'Symfony\Component\DependencyInjection\ContainerBuilder',
-            array('hasDefinition', 'findTaggedServiceIds', 'getDefinition')
+            array('hasDefinition', 'findTaggedServiceIds', 'getDefinition', 'findDefinition')
         );
         $builder->expects($this->any())
             ->method('hasDefinition')