[Libva] CPU usage regression

[Yuan, Shengquan]

>
> Yes it increases CPU usage. When starting a stream the CPU usage is low.
> Let it play for around 30 minutes and you see the usage is growing. I do
> not think that _XSend is correct. IIRC the Mesa DRI2 code uses also
> _XReplay.
>
Ok. Revert back to the original version.

Thanks
-Austin