Fix backend_name and section name mismatch

Change-Id: I16a56250dfea62630bcc096fcda194b81316da48

ops_openstack/plugins/classes.py

@@ -77,7 +77,7 @@ class CinderStoragePluginCharm(ops_openstack.core.OSBaseCharm):
 
     def set_data(self, data, config, app_name):
         """Inform another charm of the backend name and configuration."""
-        data['backend_name'] = config['volume-backend-name'] or app_name
+        data['backend_name'] = app_name
         data['stateless'] = str(self.stateless)
         data['active_active'] = str(self.active_active)
         data['subordinate_configuration'] = self.render_config(

unit_tests/test_plugins_classes.py

@@ -127,19 +127,12 @@ class TestBaseCinderCharm(unittest.TestCase):
                 juju-info:
                     interface: juju-info
                     scope: container
-            ''',
-            config='''
-            options:
-                volume-backend-name:
-                    default: ""
-                    type: string
             '''
         )
         self.addCleanup(self.harness.cleanup)
         self.harness.begin()
         self.harness.set_leader(True)
         backend = self.harness.add_relation('storage-backend', 'cinder')
-        self.harness.update_config({'volume-backend-name': 'test'})
         self.harness.add_relation_unit(backend, 'cinder/0')
 
     def test_cinder_base(self):