修改用户当前密码流程（调用系统表单）

function my_form_menu() {

  $items['user/%user/password'] = array(
    'title' => '修改密码',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('change_user_pass',1),
    'access callback' => 'user_edit_access',
    'access arguments' => array(1),
    'weight' => 0,
    'type' => MENU_LOCAL_TASK,
  );
  return $items;
}
function change_user_pass($form, &$form_state, $account) {
  $category = 'account';

  if (!isset($form_state['user'])) {
    $form_state['user'] = $account;
  }
  else {
    $account = $form_state['user'];
  }
  $form['#user'] = $account;
  $form['#user_category'] = $category;

  user_account_form($form, $form_state);
  $langcode = entity_language('user', $account);
  
  unset($form['account']['current_pass']['#description']);
  unset($form['account']['pass']['#description']);
  $form['account']['mail']['#access'] = FALSE;

  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
  );

  return $form;
}

function  change_user_pass_submit($form, &$form_state) {

  $account = $form_state['user'];
  $edit_user = array(
     'pass' => $form_state['values']['pass'],
    );
  $account_unchanged = clone $account;

  user_save($account_unchanged, $edit_user);
  $form_state['redirect'] = 'user/'.$form_state['user']->uid.'/password';
  drupal_set_message('密码修改成功');
}