WordPress - Add HTML after search form

<?php
  // WordPress tweak - add some html after the search form
  add_filter('get_search_form', 'add_shop_link');
  function add_shop_link($form) {
    $form .= '<div id="my_shop_link">';
    $form .= '<a href="/shop">Cart</a>';
    $form .= "</div>";
    return $form;
  }