Ceph » rgw

Remove bucket API¹ returns NoSuchKey but NoSuchBucket is appropriate in this case.

Code path:
RGWRadosStore::get_bucket
> RGWRadosBucket::get_bucket_info
> RGWBucketCtl::read_bucket_info
> RGWBucketCtl::read_bucket_entrypoint_info
> RGWSI_Bucket_SObj::read_bucket_entrypoint_info
> RGWSI_MetaBackend_SObj::get_entry # returns -ENOENT as is. Should convert this to -ERR_NO_SUCH_BUCKET
> rgw_get_system_obj
> RGWSI_SysObj::Obj::ROp::stat
> RGWSI_SysObj_Core::stat # return -ENOENT here.

[1]: https://docs.ceph.com/en/pacific/radosgw/adminops/#remove-bucket