Add hacking rule to prevent translating log messages

[Ngo Quoc Cuong]

Starting with the Pike series, OpenStack no longer supports log translation.
We should add a hacking rule to prevent future mistakes.

These such statements will be treated as invalidated:

LOG.debug(_(...))
LOG.error(_(...))
LOG.info(_(...))
LOG.exception(_(...))
LOG.critical(_(...))

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/478791

[Sean McGinnis (sean-mcginnis)]

This isn't a bug.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/478791
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=7b71585aa1e4bb116ce183f6e2879a1951738fc6
Submitter: Jenkins
Branch: master

commit 7b71585aa1e4bb116ce183f6e2879a1951738fc6
Author: Ngo Quoc Cuong <email address hidden>
Date: Thu Jun 29 04:04:26 2017 -0400

    Update log translation hacking rule

    Starting with the Pike series, OpenStack no longer supports log
    translation.
    Update hacking rule to prevent log translation in all log level instead
    of only debug level.

    Since all log translations are invalidated, check_explicit_underscore_import
    can be simplified.

    Change-Id: I1105fcb7e25549017ed7fcad8f932abc1b635129
    Related-Bug: #1701195