NEC driver: fix an undefined variable

Currently, NEC driver references an undefined variable in message
formatting.
That causes volume creation failure when 4 or more volumes are created
from same image in parallel.

This patch removes the reference.

Conflicts:
        cinder/tests/unit/volume/drivers/nec/test_volume.py
        Note: It is refactored in Train.

Change-Id: I3dc6a55ee5ed496a37885a139fba11d1134e971f
Closes-Bug: #1850913
(cherry picked from commit 16dbad18cc)
(cherry picked from commit 41cf3b7497)
(cherry picked from commit 16f9c5535f)

cinder/tests/unit/volume/drivers/nec/test_volume.py

@@ -671,6 +671,13 @@ class BindLDTest(volume_helper.MStorageDSVDriver, test.TestCase):
             self.vol, self.vol.size, None,
             self._convert_id2name,
             self._select_leastused_poolnumber)
+        self.mock_object(self._cli, 'get_pair_lds',
+                         return_value={'lds1', 'lds2', 'lds3'})
+        with self.assertRaisesRegex(exception.VolumeBackendAPIException,
+                                    'Cannot create clone volume. '
+                                    'number of pairs reached 3. '
+                                    'ldname=LX:287RbQoP7VdwR1WsPC2fZT'):
+            self.create_cloned_volume(self.vol, self.src)
 
     def test_bindld_CreateCloneWaitingInterval(self):
         self.assertEqual(10, cli.get_sleep_time_for_clone(0))

cinder/volume/drivers/nec/volume_helper.py

@@ -475,8 +475,7 @@ class MStorageDriver(volume_common.MStorageVolumeCommon):
             if len(pair_lds) == 3:
                 msg = (_('Cannot create clone volume. '
                          'number of pairs reached 3. '
-                         '%(msg)s. ldname=%(ldname)s') %
-                       {'msg': msg, 'ldname': source_name})
+                         'ldname=%s') % source_name)
                 LOG.error(msg)
                 raise exception.VolumeBackendAPIException(data=msg)