scsi: aic94xx: fix an error code in aic94xx_init()

We accidentally return success instead of -ENOMEM on this error path.

Fixes: 2908d778

 ("[SCSI] aic94xx: new driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>