enforce rados put aligment

Signed-off-by: Lluis Pamies-Juarez <lluis.pamies-juarez@hgst.com>
(cherry picked from commit 304b08a23a3db57010078046955a786fe3589ef8)
erasure-code: verify that rados put enforces alignment

http://tracker.ceph.com/issues/8622 refs: #8622

Signed-off-by: Loic Dachary <loic@dachary.org>
(cherry picked from commit b46c4056014dd6de5e3bd736f2c41f096ea708b4)