Issue #1886812 by kiamlaluno: theme_form_element() initialize a variable that is never used.

includes/form.inc

@@ -4009,8 +4009,6 @@ function theme_file($variables) {
  */
 function theme_form_element($variables) {
   $element = &$variables['element'];
-  // This is also used in the installer, pre-database setup.
-  $t = get_t();
 
   // This function is invoked as theme wrapper, but the rendered form element
   // may not necessarily have been processed by form_builder().