Switch to oslo_log

Change-Id: Id9ce71a53f4392ea1bd408681d01b6174d86ae61
diff --git a/patrole_tempest_plugin/rbac_rule_validation.py b/patrole_tempest_plugin/rbac_rule_validation.py
index 7785eea..e11ae4c 100644
--- a/patrole_tempest_plugin/rbac_rule_validation.py
+++ b/patrole_tempest_plugin/rbac_rule_validation.py
@@ -13,8 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import logging
-
+from oslo_log import log as logging
 from tempest import config
 from tempest.lib import exceptions