scsi: qla2xxx: edif: Reduce disruption due to multiple app start

scsi: qla2xxx: edif: Reduce disruption due to multiple app start

Multiple app start can trigger a session bounce. Make driver skip over
session teardown if app start is seen more than once.

Link: https://lore.kernel.org/r/20220608115849.16693-4-njavali@marvell.com
Fixes: 397c4e69bdb0 ("scsi: qla2xxx: edif: Add start + stop bsgs")
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.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>