[SCSI] lpfc 8.3.18: FC/FCoE Discovery fixes

FC/FCoE Discovery fixes:

- Call the lpfc_drain_txq only for SLI4 hba
- In lpfc_cmpl_els_fdisc, fix code path that does not free IOCB.
- Treated firmware matching FCF property with different index as error
- Propagate error returns from lpfc_issue_els_flogi()
- Refactored lpfc_unregister_unused_fcf() to create a post
  lpfc_dev_loss_tmo handler call for SLI-4 devices. Allows checking of
  fcf after last ndlp released so that fcf can be released if no longer
  in use.
- Replaced individual FCF_XXXX_DISC flag clearing in lieu of aggregate
  FCF_DISCOVERY flag upon succesful completion of flogi.
- Correct setting of altBbCredit value in sparams to correct issue with
  logins with remote loop-based devices.

Signed-off-by: Alex Iannicelli <alex.iannicelli@emulex.com>
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>