[PATCH] block: be more careful about status in __bio_chain_endio

If two bios are chained under the one parent (with bio_chain()) it is possible that one will succeed and the other will fail. __bio_chain_endio must ensure that the failure error status is reported for the whole, rather than the success. It currently tries to be careful, but this test is racy.

[PATCH] block: be more careful about status in __bio_chain_endio

If two bios are chained under the one parent (with bio_chain()) it is possible that one will succeed and the other will fail. __bio_chain_endio must ensure that the failure error status is reported for the whole, rather than the success. It currently tries to be careful, but this test is racy.