drm/nouveau/device: convert user class to new-style nvkm_object

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
index a59a8e5..73770fb 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
@@ -1990,7 +1990,7 @@
 			if (!nv_iclass(device, NV_SUBDEV_CLASS) &&
 			    device->parent == &nvkm_client(device)->object) {
 				struct {
-					struct nvkm_parent base;
+					struct nvkm_object base;
 					struct nvkm_device *device;
 				} *udevice = (void *)device;
 				return udevice->device;