Vote only one time

I've found a piece of code to help me (https://www.drupal.org/node/2036071#comment-10833672) :

<?php
/**
 * Alter the vote before it is saved.
 *
 * @param array $vote
 *   array(
 *     'entity_type' => $content_type,
 *     'entity_id' => $content_id,
 *     'value_type' => $widget->value_type,
 *     'value' => $value,
 *     'tag' => $widget->tag,
 *   );
 * @param array $context
 *   array(
 *     'redirect' => &$redirect, // Path. Alter to redirect the user.
 *     'save' => &$save, // Boolean indicating whether the vote must be saved.
 *     'widget' => $widget, // Widget object, unalterable.
 *   );
 */
function hook_rate_vote_alter($vote, $context) {
  $content_type = 'recette';
  $rate_widget_tag = 'concours'; //Name of the rate widget

  global $user;

  //Find votes based on criteria (Here: from the same logged-in user or IP address)
  $criteria['tag'] = $rate_widget_tag;
  $criteria['uid'] = $user->uid;
  if ($user->uid == 0 ) {
    $criteria['vote_source'] = ip_address(); //"89.134.196.161";
  }
    $votes = votingapi_select_votes($criteria);

  //Disable voting if user has already voted on another node in the same content type ($context['save'] = 0;)
  if (!empty($votes)) {
    foreach ($votes as $vote) {
      $nid = $vote['entity_id'];

      $node = node_load($nid);
      if ($node->type == $content_type) {
        $context['save'] = 0;
        print "You already voted for another node in the content type.";

        return;
      }
    }
  }
}

But it doesn't work. Can someone check why it doesn't work ?