If the taxonomy rewrite is hierarchical the $termlink is already correct. No need to add the parents.

get_term_link already makes a hierarchical link: http://core.trac.wordpress.org/browser/tags/3.6.1/wp-includes/taxonomy.php#L3107
Merge pull request #8 from KoenRijpstra/master

If the taxonomy rewrite is hierarchical the $termlink is already correct...