Cleaning up CONF.register_opts() in compute/__init__.py

This patch makes the import of oslo_config and registration
of _compute_opts consistent with all other imports and
registration statements in other files. In a future patch
that dynamically generates Cinder config options, it will now
be possible to get the options being registered in this file.

Change-Id: Ifaae49dd6d0163b5cde44df7b3ca904fb550f211

cinder/compute/__init__.py

@@ -13,21 +13,22 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import oslo_config.cfg
+from oslo_config import cfg
 from oslo_utils import importutils
 
 
-_compute_opts = [
-    oslo_config.cfg.StrOpt('compute_api_class',
-                           default='cinder.compute.nova.API',
-                           help='The full class name of the '
-                                'compute API class to use'),
+compute_opts = [
+    cfg.StrOpt('compute_api_class',
+               default='cinder.compute.nova.API',
+               help='The full class name of the '
+               'compute API class to use'),
 ]
 
-oslo_config.cfg.CONF.register_opts(_compute_opts)
+CONF = cfg.CONF
+CONF.register_opts(compute_opts)
 
 
 def API():
-    compute_api_class = oslo_config.cfg.CONF.compute_api_class
+    compute_api_class = CONF.compute_api_class
     cls = importutils.import_class(compute_api_class)
     return cls()