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>

monitor.c

@@ -1602,8 +1602,10 @@ static void do_info_status(Monitor *mon)
        monitor_printf(mon, "VM status: paused\n");
 }
 
-
-static void do_balloon(Monitor *mon, const QDict *qdict)
+/**
+ * do_balloon(): Request VM to change its memory allocation
+ */
+static void do_balloon(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     int value = qdict_get_int(qdict, "value");
     ram_addr_t target = value;

qemu-monitor.hx

@@ -874,7 +874,8 @@ ETEXI
         .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