scsi: lpfc: Fix crash due to port reset racing vs adapter error handling

scsi: lpfc: Fix crash due to port reset racing vs adapter error handling

If the adapter encounters a condition which causes the adapter to fail
(driver must detect the failure) simultaneously to a request to the driver
to reset the adapter (such as a host_reset), the reset path will be racing
with the asynchronously-detect adapter failure path.  In the failing
situation, one path has started to tear down the adapter data structures
(io_wq's) while the other path has initiated a repeat of the teardown and
is in the lpfc_sli_flush_xxx_rings path and attempting to access the
just-freed data structures.

Fix by the following:

 - In cases where an adapter failure is detected, rather than explicitly
   calling offline_eratt() to start the teardown, change the adapter state
   and let the later calls of posted work to the slowpath thread invoke the
   adapter recovery.  In essence, this means all requests to reset are
   serialized on the slowpath thread.

 - Clean up the routine that restarts the adapter. If there is a failure
   from brdreset, don't immediately error and leave things in a partial
   state. Instead, ensure the adapter state is set and finish the teardown
   of structures before returning.

 - If in the scsi host reset handler and the board fails to reset and
   restart (which can be due to parallel reset/recovery paths), instead of
   hard failing and explicitly calling offline_eratt() (which gets into the
   redundant path), just fail out and let the asynchronous path resolve the
   adapter state.

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>