nvme-fc unregister remote port

[Trapp, Darren]

During the unregister remote process, we stop all the q’s, kill the IO (including AEN’s) and try and send a disconnect to the target via a LS request.  But, that request fails since __nvme_fc_send_ls_req first checks to ensure the remote port is ONLINE.  It won’t be since the unregister_remoteport sets the state to DELETED.

The disconnect never goes to the target to make an orderly shutdown/cleanup.  The target will eventually figure it out when the keep alive’s stop coming.  But it seams we should do an orderly shutdown when we can.