scsi: aic7xxx: Return negative error codes in ahc_linux_register_host()

ahc_linux_register_host() returns both positive and negative error codes.
It's better to make this function only return negative error codes.

Signed-off-by: Su Hui <suhui@nfschina.com>
Link: https://lore.kernel.org/r/20231201025955.1584260-2-suhui@nfschina.com


Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>