scsi: aacraid: Get correct lun count

The correct lun count needs to be divided by 24, missed it in the
previous patch set.

Fixes: 4b00022753550055 (scsi: aacraid: Create helper functions to get lun info)
Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>