drm/nouveau/disp: convert to new-style nvkm_engine

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c
index f3ce583..225858e 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c
@@ -47,7 +47,7 @@
 	if (nvif_unpack(args->v0, 0, 0, false)) {
 		nvif_ioctl(parent, "create disp cursor vers %d head %d\n",
 			   args->v0.version, args->v0.head);
-		if (args->v0.head > disp->head.nr)
+		if (args->v0.head > disp->base.head.nr)
 			return -EINVAL;
 		head = args->v0.head;
 	} else