Failed LDAP logins not logged to audit log

While investigating https://gitlab.com/gitlab-org/gitlab-ce/issues/46724, I found that failed LDAP logins are not logged to the audit event log because fail_login is overriden in app/controllers/ldap/omniauth_callbacks_controller.rb but fail_login in ee/app/controllers/ee/omniauth_callbacks_controller.rb is never called.

The failed logins are logged to application.log, so it's at least there.