fixes #6970 - content host bulk actions - fix 2 regressions

Stumbled across a couple of issues that need fixing.

1. unable to perform bulk actions (via systems_bulk_actions_controller)
   due to permission denied errors
2. unable to retrieve applicable errata
Merge pull request #4538 from bbuckingham/issue-6969

fixes #6970 - content host bulk actions - fix 2 regressions