Modify the code to react more like a real HBA -> vHBA creation.

Currently the code would just modify the input XML definition to
set the name to a wwpn and then modify the scsi_host capability
entry for the defintion to change the scsi_host# and unique_id
before adding that into the node device.

This patch does things a bit better. It finds and copies a known
existing vHBA (scsi_host11) in the node_device database and modifies
that definition to change the name to scsi_host12 and set the wwnn/
wwpn to what the input XML would expect before adding the def to the
node device object list.

Then rather than create a returned "dev" using the (poorly) mocked
name - perform the lookup using the new device name.