Changed so that VMs with disks on only one host get mounted without NFS

Tested against:

• VM with only local disks - all disks were mounted locally
• VM with one local disk and one on multiple hosts - all disks were mounted with NFS
• VM with disks only on multiple hosts - all disks were mounted with NFS

Tested using: make; scp hostinfo-libvirt cloud-07:/usr/local/sbin/hostinfo-libvirt; ssh cloud-07 virsh undefine --remove-all-storage --nvram --tpm --domain twilight-gateway; ssh cloud-07 virsh undefine --remove-all-storage --nvram --tpm --domain twilight-gateway-2; ssh cloud-07 virsh undefine --remove-all-storage --nvram --tpm --domain twilight-gateway-3; for i in 1 2 3 4 5 6; do echo ""; done; ssh cloud-07 hostinfo-libvirt --host cloud-07 --vm-check --create /tmp/hostinfo.xml; for i in 1 2 3 4 5 6; do echo ""; done; ssh cloud-07 hostinfo-libvirt --host cloud-07 --vm-check --create /tmp/hostinfo-multihost.xml; for i in 1 2 3 4 5 6; do echo ""; done; ssh cloud-07 hostinfo-libvirt --host cloud-07 --vm-check --create /tmp/hostinfo-multihost-strict.xml