fix ceilometer ENABLE_SERVICES comment

- keep it aligned with the Ceilometer doc

Change-Id: Ib1ca0cfbeafc61723e5d4fe79da6355db7d76f0c
Fixes: bug #1179590
diff --git a/lib/ceilometer b/lib/ceilometer
index 1c289fd..0f0265d 100644
--- a/lib/ceilometer
+++ b/lib/ceilometer
@@ -1,8 +1,8 @@
 # lib/ceilometer
 # Install and start **Ceilometer** service
 
-# To enable, add the following to localrc
-# ENABLED_SERVICES+=ceilometer-acompute,ceilometer-acentral,ceilometer-collector,ceilometer-api
+# To enable Ceilometer services, add the following to localrc
+# enable_service ceilometer-acompute ceilometer-acentral ceilometer-collector ceilometer-api
 
 # Dependencies:
 # - functions