Fix typo in comment.

common/djangoapps/student/views.py

@@ -298,7 +298,7 @@ def complete_course_mode_info(course_id, enrollment):
 def dashboard(request):
     user = request.user
 
-    # Build our (course, enorllment) list for the user, but ignore any courses that no
+    # Build our (course, enrollment) list for the user, but ignore any courses that no
     # longer exist (because the course IDs have changed). Still, we don't delete those
     # enrollments, because it could have been a data push snafu.
     course_enrollment_pairs = []