Description of problem:

Deletion of image failed (see http://gerrit.ovirt.org/#/c/22563/),
but engine display the confusing message:
 
    Disk gluster-test was successfully removed from domain gluster with storage failure

Version-Release number of selected component (if applicable):

ovirt-engine 5ccea20c205457f70cbd480f80455f600b386836

How reproducible:

Always


Steps to Reproduce:
1. Create disk on glusterfs domain
2. Delete disk

Actual results:

Clear error message about failure to delete the disk.