Wrong variable name in functions.php, missing update to sql schema

In includes/functions.php, this:

$reading_sql = ' AND s.session_forum_id = ' . (int) $f;

should be:

$reading_sql = ' AND s.session_forum_id = ' . (int) $forum_id;

Because of the missing update of the SQL schema files, it there is an sql error in viewtopic.