Docs: Improve comments in some wp-admin files per the documentation standards.

Props passoniate.
Fixes #49215, #49216.

git-svn-id: https://develop.svn.wordpress.org/trunk@47084 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/comment.php

@@ -165,7 +165,7 @@ function get_pending_comments_num( $post_id ) {
 
 	$pending_keyed = array();
 
-	// Default to zero pending for all posts in request
+	// Default to zero pending for all posts in request.
 	foreach ( $post_id_array as $id ) {
 		$pending_keyed[ $id ] = 0;
 	}