scsi: qla2xxx: Fix reset of MPI firmware

Normally, the MPI firmware is reset when an MPI dump is collected.  If an
unsaved MPI dump exists in the driver, though, an alternate mechanism is
used. This mechanism, which was not fully correct, is not recommended and
instead an MPI dump template walk is suggested to perform the MPI reset.

To allow for the MPI dump template walk, extra space is reserved in the MPI
dump buffer which gets used only when there is already an MPI dump in
place.

Link: https://lore.kernel.org/r/20200929102152.32278-5-njavali@marvell.com
Fixes: cbb01c2f

 ("scsi: qla2xxx: Fix MPI failure AEN (8200) handling")
Cc: stable@vger.kernel.org
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>