Comment 2 for bug 1777861

Reviewed: https://review.openstack.org/576876
Committed: https://git.openstack.org/cgit/openstack/diskimage-builder/commit/?id=64bb87f7b500d95c54bae70c30507687948af963
Submitter: Zuul
Branch: master

commit 64bb87f7b500d95c54bae70c30507687948af963
Author: Yolanda Robla <email address hidden>
Date: Wed Jun 20 16:25:59 2018 +0200

    Only detach device if all partitions have been cleaned

    Currently there is a bug, that tries to detach the device from a
    partition at the first try, without considering that there may be
    other partitions and volumes on it. Ensure that the detach is done
    properly, and add a test to ensure that this happens correctly.

    Change-Id: I35c5a473509f17a70270a2cbf5bf579faaeb123a
    Fixes-Bug: #1777861