ensure variable is not empty

roles/virtualization/tasks/vmware.yml

@@ -1,4 +1,3 @@
----
 - name: Create VM in vCenter
   delegate_to: localhost
   community.vmware.vmware_guest:
@@ -33,7 +32,7 @@
         type: dhcp
   register: vmware_guest_result
   failed_when:
-    - vmware_guest_result.failed
+    - vmware_guest_result.failed is defined and vmware_guest_result.failed
     - "'error' in vmware_guest_result"
     - "'failed' in vmware_guest_result"
     - vmware_guest_result.rc is defined and vmware_guest_result.rc != 0