drm/ttm: Do not add non-system domain BO into swap list

BO would be added into swap list if it is validated into system domain.
If BO is validated again into non-system domain, say, VRAM domain. It
actually should not be in the swap list.

Signed-off-by: xinhui pan <xinhui.pan@amd.com>
Acked-by: Guchun Chen <guchun.chen@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210224032808.150465-1-xinhui.pan@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/ttm/ttm_bo.c

@@ -111,6 +111,8 @@ void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
 
 		swap = &ttm_glob.swap_lru[bo->priority];
 		list_move_tail(&bo->swap, swap);
+	} else {
+		list_del_init(&bo->swap);
 	}
 
 	if (bdev->funcs->del_from_lru_notify)