monitor: Convert do_balloon() to QObject

It is important to note that it never fails, as big refactoring
of the virtio code would be needed to get the proper error code.

Patchworks-ID: 35349
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-monitor.hx b/qemu-monitor.hx
index 8dca4f1..29999c6 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -874,7 +874,8 @@
         .args_type  = "value:i",
         .params     = "target",
         .help       = "request VM to change it's memory allocation (in MB)",
-        .mhandler.cmd = do_balloon,
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_balloon,
     },
 
 STEXI