scsi: lpfc: Fix rediscovery on switch blade pull

When the switch blade is pulled out then plugged back in, the driver
does not issue a PLOGI to the target

When the switch blade is pulled out, it does not reset the link. The
driver ends up issuing a LOGO to the target, and finally sees devloss.
Since the driver believes that a LOGO is outstanding, it does not issue
a PLOGI to the target upon link up

Correct by placing the ndlp in UNUSED state When devloss happens in
LOGO_ISSUE state.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>