Removing unused $db in Model::_deleteLinks. Fixes #6384

Author: markstory

cake/libs/model/model.php

@@ -1789,8 +1789,6 @@ function _deleteDependent($id, $cascade) {
  * @access protected
  */
 	function _deleteLinks($id) {
-		$db =& ConnectionManager::getDataSource($this->useDbConfig);
-
 		foreach ($this->hasAndBelongsToMany as $assoc => $data) {
 			$records = $this->{$data['with']}->find('all', array(
 				'conditions' => array_merge(array($this->{$data['with']}->escapeField($data['foreignKey']) => $id)),