MDL-36805 Correct docs for workshop_grade_item_update in mod_workshop
MDL-36805 Correct docs for workshop_grade_item_update in mod_workshop

The documentation suggested that the modname field should be present on the
$workshop parameter when this is not required. It is not used in any point
in the function and the $workshop variable is never passed to another
function which may use it.

dilawar/moodle