NFS cinder backend fix

Closes-Bug: #1388737
Issue: cinder volume creation fails for NFS backend.
       The NFS mount was wrongly sent along with the host string.
       Instead of sending the list as '11.1.0.1:/nfsvol', the list
       is sent as 'cmbu-ceph-2:11.1.0.1:/nfsvol'. This caused the
       NFS mount to fail.
Fix: Fixed the parser to create the list without the hostname.
Test: Verified the cinder volume creation with the change and
      verified attaching the volume to VM.

Change-Id: I5cbda9dffb940affa1435288965ea76ec9fe9e47