drm/nouveau: skip move_notify() if bo does not have a vma attached

static void

nouveau_bo_move_ntfy(struct ttm_buffer_object *bo, struct ttm_mem_reg *new_mem)

{

	struct drm_nouveau_private *dev_priv = nouveau_bdev(bo->bdev);

	struct nouveau_mem *node = new_mem->mm_node;

	struct nouveau_bo *nvbo = nouveau_bo(bo);

	struct nouveau_vma *vma = &nvbo->vma;

	struct nouveau_vm *vm = vma->vm;

	if (dev_priv->card_type < NV_50)

	if (!vma->vm)

		return;

	switch (new_mem->mem_type) {

		nouveau_vm_map(vma, node);

		break;

	case TTM_PL_TT:

		if (vma->node->type != vm->spg_shift) {

		if (vma->node->type != vma->vm->spg_shift) {

			nouveau_vm_unmap(vma);

			vma = &node->tmp_vma;

		}