Fix broken logging imports.

This fixes all of the files incorrectly importing logging directly
and removes the workaround in hacking.py that was due to improper
from nova.openstack.common.log import logging statements.

Change-Id: Icfc25dc148c4a7b5fa7f6a7b609cd6c3d94efee1

tools/hacking.py

@@ -46,7 +46,6 @@ logging.disable('LOG')
 #N9xx other
 
 IMPORT_EXCEPTIONS = ['sqlalchemy', 'migrate', 'nova.db.sqlalchemy.session',
-                     'nova.openstack.common.log.logging',
                      'nova.db.sqlalchemy.migration.versioning_api']
 # Paste is missing a __init__ in top level directory
 START_DOCSTRING_TRIPLE = ['u"""', 'r"""', '"""', "u'''", "r'''", "'''"]