Remove deprecated neutron.common.utils.ensure_dir

[Chenghui Yu]

ensure_dir implementation has been moved from neutron.agent.linux.utils and will be deprecated for removal in version Ocata. ensure_tree(path, 0o755) from oslo_utils.fileutils can be used
instead.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/522235

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/522235
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=e2ad828e0fd76290b1069a5951ef3acdf0cd039b
Submitter: Zuul
Branch: master

commit e2ad828e0fd76290b1069a5951ef3acdf0cd039b
Author: chenghuiyu <email address hidden>
Date: Wed Nov 22 18:01:01 2017 +0800

    Remove the ensure_dir

    The utils.file.ensure_dir is deprecated for removal in version Ocata.
    ensure_tree(path, 0o755) from the oslo_utils.fileutils can be used
    instead.

    Depends-On: Ic9b4b86e65052c06c33c8628bb0c6700cdfd875b
    Change-Id: Ifff970d80acb7ef28cb7fc67d3ae0c5524de1bc3
    Closes-Bug: #1733757

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 12.0.0.0b2 development milestone.