hw/audio/virtio-sound: fix heap buffer overflow

hw/audio/virtio-sound: fix heap buffer overflow

Currently, the guest may write to the device configuration space,
whereas the virtio sound device specification in chapter 5.14.4
clearly states that the fields in the device configuration space
are driver-read-only.

Remove the set_config function from the virtio_snd class.

This also prevents a heap buffer overflow. See QEMU issue #2296.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2296
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20240901130112.8242-1-vr_qemu@t-online.de>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>