hw/input: Constify VMState

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231221031652.119827-34-richard.henderson@linaro.org>
diff --git a/hw/input/virtio-input.c b/hw/input/virtio-input.c
index 5b5398b..3bcdae4 100644
--- a/hw/input/virtio-input.c
+++ b/hw/input/virtio-input.c
@@ -293,7 +293,7 @@
     .name = "virtio-input",
     .minimum_version_id = VIRTIO_INPUT_VM_VERSION,
     .version_id = VIRTIO_INPUT_VM_VERSION,
-    .fields = (VMStateField[]) {
+    .fields = (const VMStateField[]) {
         VMSTATE_VIRTIO_DEVICE,
         VMSTATE_END_OF_LIST()
     },