Use the passed in workflow when creating or updating a plan
Use the passed in workflow when creating or updating a plan

This was previously changed by mistake in a bad merge which
caused th CLI to always call the create plan workflow.
See: I9d77880e82ec429a2ea340df87c89055a09e9720

Partial-Bug: #1622683
Change-Id: I8967b8badfeee1ba9ad473171103c7c37d6f7209

openstack/python-tripleoclient