Fix placement service for identity-v3

The domain_name to be used needs to be $SERVICE_DOMAIN_NAME, as this is
changed in devstack from "Default" to "service".

Change-Id: I6351c1b2ca7ea4448e13eb87455bff4058df4fa7
diff --git a/lib/placement b/lib/placement
index 93b72eb..871e282 100644
--- a/lib/placement
+++ b/lib/placement
@@ -103,9 +103,9 @@
     iniset $NOVA_CONF placement auth_url "$KEYSTONE_SERVICE_PROTOCOL://$KEYSTONE_SERVICE_HOST:$KEYSTONE_AUTH_PORT/v3"
     iniset $NOVA_CONF placement username placement
     iniset $NOVA_CONF placement password "$SERVICE_PASSWORD"
-    iniset $NOVA_CONF placement user_domain_name "Default"
+    iniset $NOVA_CONF placement user_domain_name "$SERVICE_DOMAIN_NAME"
     iniset $NOVA_CONF placement project_name "$SERVICE_TENANT_NAME"
-    iniset $NOVA_CONF placement project_domain_name "Default"
+    iniset $NOVA_CONF placement project_domain_name "$SERVICE_DOMAIN_NAME"
     iniset $NOVA_CONF placement os_region_name "$REGION_NAME"
     # TODO(cdent): auth_strategy, which is common to see in these
     # blocks is not currently used here. For the time being the