sx8: fix an error code in carm_init_one()

Return a negative error code here on this error path instead of
returning success.

Fixes: 637208e7 ("block/sx8: add error handling support for add_disk()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211001122722.GC2283@kili


Signed-off-by: Jens Axboe <axboe@kernel.dk>