title: get_next_post_link() and get_previous_post_link() return wrong posts
body: <p>I'm using <code>get_next_post_link()</code> and <code>get_previous_post_link()</code> within the loop but the returned posts are not correct.</p>
  
  <p><code>get_next_post_link()</code> shows the previous post and <code>get_previous_post_link()</code> gives the current post. Below the context of these links:</p>
  
  <pre><code>$args['name'] = $postname;
  $query = new WP_Query($args);
  
  if($query-&gt;have_posts())
      {
      while ($query-&gt;have_posts())
          {
          $query-&gt;the_post();
  
          $id         = get_the_ID();
          $title          = get_the_title();
          $content        = get_the_content();
  
          $nextpost       = get_next_post_link('Next: %link');
          $previouspost   = get_previous_post_link('Prev: %link');
          }
      }
  </code></pre>