Change perms for the VM logs

When logs were under a directory without read permissions,
bifrost was not able to create the vm log files for centos/suse
and were not published.

Change-Id: Ifcc31c611edd34acb4fc3c1bb67bbe2a528d93cc

playbooks/roles/bifrost-create-vm-nodes/tasks/prepare_libvirt.yml

@@ -118,7 +118,9 @@
   file:
     state: directory
     path: "{{ test_vm_logdir }}"
-    mode: "o+rx"
+
+- name: Add read/execute perms for the whole directory path
+  shell: f="{{ test_vm_logdir }}" ; while [[ $f != "/" ]]; do chmod 0755 $f; f=$(dirname $f); done;
 
 - name: install virtualbmc
   pip: