Undefined variable: overall in award_criteria_courseset.php

PHP error message:

PHP Notice: Undefined variable: overall in /www/badges/criteria/award_criteria_courseset.php on line 241

This happens if there are no values to be reviewed. In this case the foreach loop in line 200 is not executed and variable overall is not defined.

Suggested change in line 241:
return isset($overall) ? $overall: false;