drm/nouveau/nvif: modify nvif_unvers/nvif_unpack macros to be more obvious

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_usif.c b/drivers/gpu/drm/nouveau/nouveau_usif.c
index 6ae1b34..e9f52ef 100644
--- a/drivers/gpu/drm/nouveau/nouveau_usif.c
+++ b/drivers/gpu/drm/nouveau/nouveau_usif.c
@@ -130,20 +130,21 @@
 		struct nvif_notify_req_v0 v0;
 	} *req;
 	struct usif_notify *ntfy;
-	int ret;
+	int ret = -ENOSYS;
 
-	if (nvif_unpack(args->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, true))) {
 		if (usif_notify_find(f, args->v0.index))
 			return -EEXIST;
 	} else
 		return ret;
 	req = data;
+	ret = -ENOSYS;
 
 	if (!(ntfy = kmalloc(sizeof(*ntfy), GFP_KERNEL)))
 		return -ENOMEM;
 	atomic_set(&ntfy->enabled, 0);
 
-	if (nvif_unpack(req->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(ret, &data, &size, req->v0, 0, 0, true))) {
 		ntfy->reply = sizeof(struct nvif_notify_rep_v0) + req->v0.reply;
 		ntfy->route = req->v0.route;
 		ntfy->token = req->v0.token;
@@ -171,9 +172,9 @@
 		struct nvif_ioctl_ntfy_del_v0 v0;
 	} *args = data;
 	struct usif_notify *ntfy;
-	int ret;
+	int ret = -ENOSYS;
 
-	if (nvif_unpack(args->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, true))) {
 		if (!(ntfy = usif_notify_find(f, args->v0.index)))
 			return -ENOENT;
 	} else
@@ -194,9 +195,9 @@
 		struct nvif_ioctl_ntfy_del_v0 v0;
 	} *args = data;
 	struct usif_notify *ntfy;
-	int ret;
+	int ret = -ENOSYS;
 
-	if (nvif_unpack(args->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, true))) {
 		if (!(ntfy = usif_notify_find(f, args->v0.index)))
 			return -ENOENT;
 	} else
@@ -233,9 +234,9 @@
 		struct nvif_ioctl_ntfy_put_v0 v0;
 	} *args = data;
 	struct usif_notify *ntfy;
-	int ret;
+	int ret = -ENOSYS;
 
-	if (nvif_unpack(args->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, true))) {
 		if (!(ntfy = usif_notify_find(f, args->v0.index)))
 			return -ENOENT;
 	} else
@@ -270,13 +271,13 @@
 		struct nvif_ioctl_new_v0 v0;
 	} *args = data;
 	struct usif_object *object;
-	int ret;
+	int ret = -ENOSYS;
 
 	if (!(object = kmalloc(sizeof(*object), GFP_KERNEL)))
 		return -ENOMEM;
 	list_add(&object->head, &cli->objects);
 
-	if (nvif_unpack(args->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, true))) {
 		object->route = args->v0.route;
 		object->token = args->v0.token;
 		args->v0.route = NVDRM_OBJECT_USIF;
@@ -310,7 +311,7 @@
 	if (ret = -EFAULT, copy_from_user(argv, user, size))
 		goto done;
 
-	if (nvif_unpack(argv->v0, 0, 0, true)) {
+	if (!(ret = nvif_unpack(-ENOSYS, &data, &size, argv->v0, 0, 0, true))) {
 		/* block access to objects not created via this interface */
 		owner = argv->v0.owner;
 		if (argv->v0.object == 0ULL)