pass job, not batch, to perform_batch

refs CNVS-12606

Change-Id: I77a937d55fe3b29fd57f0c0a495514f7576b32c0
Reviewed-on: https://gerrit.instructure.com/33852
Reviewed-by: Rob Orton <rob@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>
QA-Review: Rob Orton <rob@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>