drm/ttm: stop destroying pinned ghost object

Daniel added a warning for this, but we were abusing that behavior here.
Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 57fcd550 ("drm/ttm: Warn on pinning without holding a reference")
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/series/84456/

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -310,7 +310,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 	kref_init(&fbo->base.kref);
 	fbo->base.destroy = &ttm_transfered_destroy;
 	fbo->base.acc_size = 0;
-	fbo->base.pin_count = 1;
+	fbo->base.pin_count = 0;
 	if (bo->type != ttm_bo_type_sg)
 		fbo->base.base.resv = &fbo->base.base._resv;
 
@@ -319,6 +319,8 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 	ret = dma_resv_trylock(&fbo->base.base._resv);
 	WARN_ON(!ret);
 
+	ttm_bo_move_to_lru_tail_unlocked(&fbo->base);
+
 	*new_obj = &fbo->base;
 	return 0;
 }