[SCSI] libfc: Change state to NONE in fc_lport_destroy

[SCSI] libfc: Change state to NONE in fc_lport_destroy

After lport_destroy, the local port should not be used again. Transition
to state NONE, any incoming frames or link up should not transition out
of this state since we are deleting exchange table and cleaning up the
local port. Also, mark link as down.

Signed-off-by: Abhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>