drm/nouveau/secboot: fix NULL pointer dereference

The msgqueue pointer validity should be checked by its owner, not by the
msgqueue code itself to avoid this situation.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/sec2/base.c

@@ -59,6 +59,13 @@ static void
 nvkm_sec2_recv(struct work_struct *work)
 {
 	struct nvkm_sec2 *sec2 = container_of(work, typeof(*sec2), work);
+
+	if (!sec2->queue) {
+		nvkm_warn(&sec2->engine.subdev,
+			  "recv function called while no firmware set!\n");
+		return;
+	}
+
 	nvkm_msgqueue_recv(sec2->queue);
 }