Add default for volume.device

Author: markgoddard

tasks/volumes.yml

@@ -26,7 +26,7 @@
     -b {{ item.backing_image }}
     {% endif %}
   with_items: "{{ volumes }}"
-  when: "{{ item.device == 'disk' }}"
+  when: "{{ item.device | default(libvirt_volume_default_device) == 'disk' }}"
   environment: "{{ libvirt_vm_script_env }}"
   register: volume_result
   changed_when: