drm/ttm: fix missing parameter change for ttm_bo_cleanup_refs

Missed in the patche:
dc947770 drm/ttm: enable swapout for reserved BOs during allocation.
don't unreserve the BO if it is not reserved by itself.

Signed-off-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>