Remove unused CONF and LOG

This is to remove unused CONF and LOG to keep code clean.

Change-Id: I57aaa3816e28c08c8e82e4717dfb1c2f99ed9ec2
diff --git a/tempest/api/compute/security_groups/test_security_group_rules.py b/tempest/api/compute/security_groups/test_security_group_rules.py
index b82fa3b..a50933b 100644
--- a/tempest/api/compute/security_groups/test_security_group_rules.py
+++ b/tempest/api/compute/security_groups/test_security_group_rules.py
@@ -14,12 +14,9 @@
 #    under the License.
 
 from tempest.api.compute.security_groups import base
-from tempest import config
 from tempest.lib import decorators
 from tempest import test
 
-CONF = config.CONF
-
 
 class SecurityGroupRulesTestJSON(base.BaseSecurityGroupsTest):
 
diff --git a/tempest/api/compute/volumes/test_attach_volume.py b/tempest/api/compute/volumes/test_attach_volume.py
index 73c7614..b63d290 100644
--- a/tempest/api/compute/volumes/test_attach_volume.py
+++ b/tempest/api/compute/volumes/test_attach_volume.py
@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from oslo_log import log as logging
 import testtools
 
 from tempest.api.compute import base
@@ -25,8 +24,6 @@
 
 CONF = config.CONF
 
-LOG = logging.getLogger(__name__)
-
 
 class AttachVolumeTestJSON(base.BaseV2ComputeTest):
     max_microversion = '2.19'
diff --git a/tempest/api/volume/admin/test_volume_services.py b/tempest/api/volume/admin/test_volume_services.py
index 2088a44..a595462 100644
--- a/tempest/api/volume/admin/test_volume_services.py
+++ b/tempest/api/volume/admin/test_volume_services.py
@@ -13,13 +13,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 from tempest.api.volume import base
-from tempest import config
 from tempest.lib import decorators
 
 
-CONF = config.CONF
-
-
 def _get_host(host):
     return host.split('@')[0]