Spell out duplicate hook locations.

props DrewAPicture.
fixes #25658.


git-svn-id: https://develop.svn.wordpress.org/trunk@25868 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/comment.php

@@ -1772,6 +1772,7 @@ function do_trackbacks($post_id) {
 	$excerpt = str_replace(']]>', ']]>', $excerpt);
 	$excerpt = wp_html_excerpt($excerpt, 252, '…');
 
+	/** This filter is documented in wp-includes/post-template.php */
 	$post_title = apply_filters('the_title', $post->post_title, $post->ID);
 	$post_title = strip_tags($post_title);