Minor fixes to help integration of CORD-912

Change-Id: I8dd69bf2eae091ca60bbbfbfebce465405662a58
diff --git a/deploy-onos-playbook.yml b/deploy-onos-playbook.yml
index 67ff1b4..dce692b 100644
--- a/deploy-onos-playbook.yml
+++ b/deploy-onos-playbook.yml
@@ -3,7 +3,7 @@
 # Deploys ONOS in Docker containers on the CORD head node
 
 - name: Include vars
-  hosts: all
+  hosts: head
   tasks:
     - name: Include variables
       include_vars: "{{ item }}"
@@ -15,5 +15,6 @@
   hosts: head
   roles:
     - onos-cord-install
-    - onos-fabric-install
+    - { role: onos-fabric-install, when: use_fabric }
+