drm/nouveau/acr: Abort loading ACR if no firmware was found

This fixes a NULL pointer access inside nvkm_acr_oneinit in case necessary
firmware files couldn't be loaded.

Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/212
Fixes: 4b569ded ("drm/nouveau/acr/ga102: initial support")
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230522201838.1496622-1-kherbst@redhat.com

drivers/gpu/drm/nouveau/nvkm/subdev/acr/base.c

@@ -224,7 +224,7 @@ nvkm_acr_oneinit(struct nvkm_subdev *subdev)
 	u64 falcons;
 	int ret, i;
 
-	if (list_empty(&acr->hsfw)) {
+	if (list_empty(&acr->hsfw) || !acr->func || !acr->func->wpr_layout) {
 		nvkm_debug(subdev, "No HSFW(s)\n");
 		nvkm_acr_cleanup(acr);
 		return 0;