shrink_pages is in unit of Order after ttm_page_pool_free,
but it is used by nr_free in next round so need change
it into native page unit
Signed-off-by: NMonk Liu <Monk.Liu@amd.com>
Reviewed-by: NRoger He <Hongbo.He@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>