input: fix memory leak

If kbd_queue is not empty and queue_count >= queue_limit,
we should free evt.

Change-Id: Ieeacf90d5e7e370a40452ec79031912d8b864d83
Signed-off-by: Nlinzhecheng <linzhecheng@huawei.com>
Message-id: 20171225023730.5512-1-linzhecheng@huawei.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

ui/input.c

@@ -421,6 +421,8 @@ void qemu_input_event_send_key(QemuConsole *src, KeyValue *key, bool down)
     } else if (queue_count < queue_limit) {
         qemu_input_queue_event(&kbd_queue, src, evt);
         qemu_input_queue_sync(&kbd_queue);
+    } else {
+        qapi_free_InputEvent(evt);
     }
 }