Attempt to register the node in the case where it must perform fence_scsi
    fencing but is not registered with the device(s) that must be fence. With
    SCSI persistent reservations, in order to do a "preempt and abort" (which
    we are using to fence a node), the node doing this operation must be
    registered with the device. This fix will check to see the the node that
    is performing the fencing is registered with the device(s). If it is not,
    then it attempts to register with the device(s) so that it can then
    continue with the fence operation normally. Note that this situation should
    never happen, especially if things are configured properly.