virtio-input: free config list

Clear the list when finalizing. The list is created during realize with
virtio_input_idstr_config() and later by further calls to
virtio_input_init_config() and virtio_input_add_config().

This leak can be reproduced with device-introspect-test -p
/x86_64/device/introspect/concrete.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>

hw/input/virtio-input.c

@@ -270,6 +270,16 @@ static void virtio_input_device_realize(DeviceState *dev, Error **errp)
     vinput->sts = virtio_add_queue(vdev, 64, virtio_input_handle_sts);
 }
 
+static void virtio_input_finalize(Object *obj)
+{
+    VirtIOInput *vinput = VIRTIO_INPUT(obj);
+    VirtIOInputConfig *cfg, *next;
+
+    QTAILQ_FOREACH_SAFE(cfg, &vinput->cfg_list, node, next) {
+        QTAILQ_REMOVE(&vinput->cfg_list, cfg, node);
+        g_free(cfg);
+    }
+}
 static void virtio_input_device_unrealize(DeviceState *dev, Error **errp)
 {
     VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(dev);
@@ -318,6 +328,7 @@ static const TypeInfo virtio_input_info = {
     .class_size    = sizeof(VirtIOInputClass),
     .class_init    = virtio_input_class_init,
     .abstract      = true,
+    .instance_finalize = virtio_input_finalize,
 };
 
 /* ----------------------------------------------------------------- */