fix null value sent to nova quota update
diff --git a/xos/openstack_observer/steps/sync_controller_slices.py b/xos/openstack_observer/steps/sync_controller_slices.py
index 1a6f517..ef69496 100644
--- a/xos/openstack_observer/steps/sync_controller_slices.py
+++ b/xos/openstack_observer/steps/sync_controller_slices.py
@@ -60,7 +60,7 @@
         if (not controller_slice.tenant_id):
             try:
                 driver = OpenStackDriver().admin_driver(controller=controller_slice.controller)
-                driver.shell.nova.quotas.update(tenant_id=controller_slice.tenant_id, instances=int(controller_slice.slice.max_slivers))
+                driver.shell.nova.quotas.update(tenant_id=tenant_id, instances=int(controller_slice.slice.max_slivers))
             except:
                 logger.log_exc('Could not update quota for %s'%controller_slice.slice.name)
                 raise Exception('Could not update quota for %s'%controller_slice.slice.name)