server: Add infrastructure for ioctl server request.
diff --git a/server/queue.c b/server/queue.c
index fa80d62..85e0856 100644
--- a/server/queue.c
+++ b/server/queue.c
@@ -168,6 +168,7 @@
     msg_queue_poll_event,        /* poll_event */
     NULL,                        /* flush */
     NULL,                        /* get_fd_type */
+    NULL,                        /* ioctl */
     NULL,                        /* queue_async */
     NULL,                        /* reselect_async */
     NULL                         /* cancel async */