In many WordPress themes developers make mistake of linking single post to itself which is not necessary. I mean why anybody will reload the single post page when he is already at the same single post page by clicking the title of that same post? The title of single post is linked to the same page in many many WordPress themes. This is against the quality standards of webmasters.
Besides Google can also ban you in this case because many publishers use the ad code below the post title and above the content. That is the title link is above and right below are the Google AdSense ads. Google mentions to remove ads from that location because users can get confused and take those ads as a part of post title or use sponsored links or advertisements text above ads in this case.
Even besides, why use that title link to the same page? Use only title without link at the single post.