Cleanup based on review.

.github/CODEOWNERS

@@ -1,6 +1,7 @@
 # This does not cover all the code in edx-platform but it's a good start.
 
 # Core
+common/djangoapps/student/
 common/djangoapps/third_party_auth/
 common/lib/xmodule/xmodule/
 lms/djangoapps/course_api/blocks
@@ -19,7 +20,6 @@ openedx/features/course_experience/
 common/lib/xmodule/xmodule/capa_module.py
 common/lib/xmodule/xmodule/html_module.py
 common/lib/xmodule/xmodule/video_module
-lms/djangoapps/courseware/
 lms/djangoapps/discussion/
 lms/djangoapps/discussion_api/
 lms/djangoapps/edxnotes
@@ -34,9 +34,6 @@ lms/djangoapps/certificates/
 # Discovery
 common/djangoapps/course_modes/
 common/djangoapps/enrollment/
-common/djangoapps/student
 lms/djangoapps/commerce/
-lms/djangoapps/courseware/
 lms/djangoapps/experiments/
 lms/djangoapps/learner_dashboard/
-lms/djangoapps/mobile_api/