monitor: convert do_device_del() to QObject, QError

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/qemu-monitor.hx b/qemu-monitor.hx
index 5308f36..d290b4b 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -589,7 +589,8 @@
         .args_type  = "id:s",
         .params     = "device",
         .help       = "remove device",
-        .mhandler.cmd = do_device_del,
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_device_del,
     },
 
 STEXI