ReplicatedBackend: populate recovery_info.size for clone (bug symptom is size mismatch on replicated backend on a clone in scrub)
This apparently never got filled in. It wasn't actually a problem since we do populate the the copy and clone subsets and the size is really only used for that. However, we now use the size to truncate out to the right size for the case where the end of the file is a hole (b5381c22a7b0d8d4c14cd8feb3a115f7d80d5d81). This didn't actually cause a failure until wip-proxy-write merged with a bug in ceph-test-rados causing an empty write past the end of the file resulting in such a hole.