Fixed missing return

src/features/navbar/GradingNav.tsx

@@ -73,7 +73,7 @@ const GradingNav: React.FC = () => {
   }, [studentList]);
 
   if (studentList.length === 0) {
-    <span>{studentNameFromInfo(activityInfo.studentInfo)}</span>;
+    return <span>{studentNameFromInfo(activityInfo.studentInfo)}</span>;
   }
 
   const firstNid = studentList[0].nid as number;