scsi: qla2xxx: edif: Flush stale events and msgs on session down

scsi: qla2xxx: edif: Flush stale events and msgs on session down

On session down, driver will flush all stale messages and doorbell
events. This prevents authentication application from having to process
stale data.

Link: https://lore.kernel.org/r/20211026115412.27691-7-njavali@marvell.com
Fixes: 4de067e5df12 ("scsi: qla2xxx: edif: Add N2N support for EDIF")
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Co-developed-by: Karunakara Merugu <kmerugu@marvell.com>
Signed-off-by: Karunakara Merugu <kmerugu@marvell.com>
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>