scsi: qla2xxx: Fix device loss on 4G and older HBAs

Due to a bug in the older scan logic, when a once lost device re-appeared,
it was not discovered. Fix this by resetting login_retry counter upon
device discovery.

This is applicable only for 4G and older HBAs.

Link: https://lore.kernel.org/r/20201202132312.19966-15-njavali@marvell.com


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>