scsi: dc395x: Fix warning using plain integer as NULL

Sparse static analysis tool generates a warning with this message "Using
plain integer as NULL pointer". Fix it.

Signed-off-by: Abhinav Singh <singhabhinav9051571833@gmail.com>
Link: https://lore.kernel.org/r/20231109215049.1466431-1-singhabhinav9051571833@gmail.com


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>