rgw: fix bucket-id assignment
rgw: fix bucket-id assignment

Get the version from the same io_ctx that you write with.

Also, use a private one, so that we don't race with other threads.

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph