get rid of deprecated syntax

roles/docker/tasks/main.yml

@@ -3,7 +3,7 @@
   - name: Check for mandatory variables required by this playbook
     fail:
       msg: "This playbook requires {{item}} to be set."
-    when: "{{ item }} is not defined or {{ item }} == ''"
+    when: "item is not defined or item == ''"
     with_items:
     - docker_storage_vg
     tags: docker-storage

roles/name-resolution/tasks/main.yml

@@ -3,7 +3,7 @@
   - name: Check for mandatory variables required by this playbook
     fail:
       msg: "This playbook requires {{item}} to be set."
-    when: "{{ item }} is not defined or {{ item }} == ''"
+    when: "item is not defined or item == ''"
     with_items:
     - lab_dns_suffix
     - openshift_master_default_subdomain