Add judgie condition after live-migration with volume

when server live-migration with volume ,after success of live_migration,
we should check the volume is whether attach or not.

Change-Id: I2bfd993f67e3fc7a00cd9ed1dfdfdf78516f6085
diff --git a/tempest/api/compute/admin/test_live_migration.py b/tempest/api/compute/admin/test_live_migration.py
index 0ceb13c..4d0f12a 100644
--- a/tempest/api/compute/admin/test_live_migration.py
+++ b/tempest/api/compute/admin/test_live_migration.py
@@ -162,11 +162,17 @@
 
         # Attach the volume to the server
         self.attach_volume(server, volume, device='/dev/xvdb')
-
+        server = self.admin_servers_client.show_server(server_id)['server']
+        volume_id1 = server["os-extended-volumes:volumes_attached"][0]["id"]
         self._migrate_server_to(server_id, target_host)
         waiters.wait_for_server_status(self.servers_client,
                                        server_id, 'ACTIVE')
+
+        server = self.admin_servers_client.show_server(server_id)['server']
+        volume_id2 = server["os-extended-volumes:volumes_attached"][0]["id"]
+
         self.assertEqual(target_host, self._get_host_for_server(server_id))
+        self.assertEqual(volume_id1, volume_id2)
 
 
 class LiveAutoBlockMigrationV225TestJSON(LiveBlockMigrationTestJSON):