Remove unused get_class call on MoreLink

Problem/Motivation

There's an unused call to get_class in core/lib/Drupal/Core/Render/Element/MoreLink.php

  public function getInfo() {
    $class = get_class($this);
    $info = parent::getInfo();
    return array(
      '#title' => $this->t('More'),
      '#theme_wrappers' => array(
        'container' => array(
          '#attributes' => array('class' => array('more-link')),
        ),
      ),
    ) + $info;
  }

Proposed resolution

Remove the extra call.