Remove third parameter from createFormBuilder call

Author: Hocdoc

components/form/introduction.rst

@@ -526,7 +526,7 @@ by ``handleRequest()`` to determine whether a form has been submitted):
 
         public function searchAction()
         {
-            $formBuilder = $this->createFormBuilder('form', null, array(
+            $formBuilder = $this->createFormBuilder(null, array(
                 'action' => '/search',
                 'method' => 'GET',
             ));