scsi: lpfc: Fix list corruption in lpfc_sli_get_iocbq

scsi: lpfc: Fix list corruption in lpfc_sli_get_iocbq

After study, it was determined there was a double free of a CT iocb during
execution of lpfc_offline_prep and lpfc_offline.  The prep routine issued
an abort for some CT iocbs, but the aborts did not complete fast enough for
a subsequent routine that waits for completion. Thus the driver proceeded
to lpfc_offline, which releases any pending iocbs. Unfortunately, the
completions for the aborts were then received which re-released the ct
iocbs.

Turns out the issue for why the aborts didn't complete fast enough was not
their time on the wire/in the adapter. It was the lpfc_work_done routine,
which requires the adapter state to be UP before it calls
lpfc_sli_handle_slow_ring_event() to process the completions. The issue is
the prep routine takes the link down as part of it's processing.

To fix, the following was performed:

 - Prevent the offline routine from releasing iocbs that have had aborts
   issued on them. Defer to the abort completions. Also means the driver
   fully waits for the completions.  Given this change, the recognition of
   "driver-generated" status which then releases the iocb is no longer
   valid. As such, the change made in the commit 99c3f08e89fb is reverted.
   As recognition of "driver-generated" status is no longer valid, this
   patch reverts the changes made in
   commit 99c3f08e89fb ("scsi: lpfc: Fix leak of ELS completions on adapter reset")

 - Modify lpfc_work_done to allow slow path completions so that the abort
   completions aren't ignored.

 - Updated the fdmi path to recognize a CT request that fails due to the
   port being unusable. This stops FDMI retries. FDMI will be restarted on
   next link up.

Link: https://lore.kernel.org/r/20190922035906.10977-14-jsmart2021@gmail.com
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>