scsi: qla2xxx: Fix disk failure to rediscover

User experienced some of the LUN failed to get rediscovered after long
cable pull test. The issue is triggered by a race condition between driver
setting session online state vs starting the LUN scan process at the same
time. Current code set the online state after notifying the session is
available. In this case, trigger to start the LUN scan process happened
before driver could set the session in online state.  LUN scan ends up with
failure due to the session online check was failing.

Set the online state before reporting of the availability of the session.

Link: https://lore.kernel.org/r/20220310092604.22950-3-njavali@marvell.com
Fixes: aecf0434

 ("scsi: qla2xxx: Fix Remote port registration")
Cc: stable@vger.kernel.org
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>