aic7770_config() returns both negative and positive error codes.  It's
better to make aic7770_probe() only return negative error codes.

A previous commit made ahc_linux_register_host() return negative error
codes, which makes sure aic7770_probe() returns negative error codes.
Signed-off-by: Su Hui <suhui@nfschina.com>
Link: https://lore.kernel.org/r/20231201025955.1584260-4-suhui@nfschina.comReviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>