Use olso.log directly

As the openstack/common is deprecated, Watcher should use oslo lib
directly to run in the openstack env. So there is much work to do
with oslo. This patch fixed the log part.

Change-Id: I3145a842fe3a22b3d08fec60d180329073edd50f

watcher/db/sqlalchemy/api.py

@@ -21,6 +21,7 @@ from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_db.sqlalchemy import session as db_session
 from oslo_db.sqlalchemy import utils as db_utils
+from oslo_log import log
 from sqlalchemy.orm.exc import MultipleResultsFound
 from sqlalchemy.orm.exc import NoResultFound
 
@@ -30,7 +31,6 @@ from watcher.db import api
 from watcher.db.sqlalchemy import models
 from watcher.objects.audit import AuditStatus
 from watcher.openstack.common._i18n import _
-from watcher.openstack.common import log
 
 CONF = cfg.CONF