Issue #1445224 follow-up by xjm: Fixed more broken tests.

core/modules/system/tests/modules/form_test/form_test.module

@@ -2133,7 +2133,7 @@ function form_test_checkboxes_zero($form, &$form_state, $json = TRUE) {
     '#value' => 'Save',
   );
   if ($json) {
-    $form['#submit'][] = '_form_test_checkbox_submit';
+    $form['#submit'][] = '_form_test_submit_values_json';
   }
   else {
     $form['#submit'][] = '_form_test_checkboxes_zero_no_redirect';