fix openvswich region param

Change-Id: I38bc2f5bfd0b5c4e5e848d057dc40853ba13eb42
diff --git a/neutron/control/openvswitch/cluster.yml b/neutron/control/openvswitch/cluster.yml
index cc39b0a..dc8e0c5 100644
--- a/neutron/control/openvswitch/cluster.yml
+++ b/neutron/control/openvswitch/cluster.yml
@@ -23,11 +23,11 @@
           ovs:
             driver: openvswitch
       compute:
-        region: $_param:openstack_region}
+        region: ${_param:openstack_region}
       database:
         host: ${_param:openstack_database_address}
       identity:
-        region: $_param:openstack_region}
+        region: ${_param:openstack_region}
       message_queue:
         members:
           - host: ${_param:openstack_message_queue_node01_address}