fix vars and playbook for simulate-fabric
diff --git a/roles/simulate-fabric/files/simulate-fabric-playbook.yml b/roles/simulate-fabric/files/simulate-fabric-playbook.yml
index 60359a3..9ff2345 100644
--- a/roles/simulate-fabric/files/simulate-fabric-playbook.yml
+++ b/roles/simulate-fabric/files/simulate-fabric-playbook.yml
@@ -17,7 +17,7 @@
        - bridge-utils
 
     - name: Create bridges
-      when: "ansible_interfaces[item.name] is not defined"
+      when: "ansible_{{ item.name }} is not defined"
       command: brctl addbr "{{ item.name }}"
       with_items: "{{ simfabric_bridges }}"