drm/tegra: Test for imported buffers with drm_gem_is_imported()

Instead of testing import_attach for imported GEM buffers, invoke
drm_gem_is_imported() to do the test.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20250619113100.70292-2-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/tegra/gem.c

@@ -523,7 +523,7 @@ void tegra_bo_free_object(struct drm_gem_object *gem)
 	if (tegra->domain) {
 		tegra_bo_iommu_unmap(tegra, bo);
 
-		if (gem->import_attach) {
+		if (drm_gem_is_imported(gem)) {
 			dma_buf_unmap_attachment_unlocked(gem->import_attach, bo->sgt,
 							  DMA_TO_DEVICE);
 			dma_buf_detach(gem->import_attach->dmabuf, gem->import_attach);