drm/nouveau: silence a debug message triggered by newer userspace

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_abi16.c

@@ -179,7 +179,7 @@ nouveau_abi16_ioctl_grobj_alloc(ABI16_IOCTL_ARGS)
 			return 0;
 	} else
 	if (init->class == 0x906e) {
-		NV_ERROR(dev, "906e not supported yet\n");
+		NV_DEBUG(dev, "906e not supported yet\n");
 		return -EINVAL;
 	}