MDL-78889 gradereport_user: Fix pass/fail icon for totals with hidden…

… items

When category total has grade to pass set it, pass fail icon was shown
even though the category total grade value was hidden.

grade/report/user/classes/report/user.php

@@ -650,7 +650,7 @@ private function fill_table_recursive(array &$element) {
                         $gradestatusclass = '';
                         $gradepassicon = '';
                         $ispassinggrade = $gradegrade->is_passed($gradegrade->grade_item);
-                        if (!is_null($ispassinggrade)) {
+                        if (!is_null($gradeval) && !is_null($ispassinggrade)) {
                             $gradestatusclass = $ispassinggrade ? 'gradepass' : 'gradefail';
                             if ($ispassinggrade) {
                                 $gradepassicon = $OUTPUT->pix_icon(