monitor: convert do_cpu_set() to QObject, QError

Signed-off-by: Markus Armbruster <[email protected]>
Signed-off-by: Anthony Liguori <[email protected]>
diff --git a/qemu-monitor.hx b/qemu-monitor.hx
index 1aa7818..415734a 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -573,7 +573,8 @@
         .args_type  = "index:i",
         .params     = "index",
         .help       = "set the default CPU",
-        .mhandler.cmd = do_cpu_set,
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_cpu_set,
     },
 
 STEXI