fix ember quiz index edit link regression

closes CNVS-12256

regression introduced with the switch to ember-data.

test plan:
  - enable fabulous quizzes flag on Account.default.settings
  - as instructor navigate to quiz index
  - click drop down for any quiz
  - select the edit link
  - verify that quiz edit page loads for selected quiz

Change-Id: Id47c0c00509cad0e8de314a34ecdd23bf3cd63b5
Reviewed-on: https://gerrit.instructure.com/32982
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Josh Simpson <jsimpson@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Jason Madsen <jmadsen@instructure.com>