In case of a non-recovery XA rollback/commit in the same connection,
thon->rollback is called instead of rollback_by_xid, Though previously,
thd_ha_data was moved to thd->transaction->xid_state.xid in hton->prepare.

Like it wasn't enough, XA PREPARE can be skipped upon user and thus we
can end up in hton->commit/rollback with and unprepared XA, so checking
xid_state.is_explicit_XA is not enough -- we should check
xid_state.get_state_code() == XA_PREPARED, which will also guarantee
is_explicit_XA() == true.