[HEVC FEI SAMPLE] fix PictStruct for extern RefList control
[HEVC FEI SAMPLE] fix PictStruct for extern RefList control

Set external picture structure value to mfxSurface structure,
otherwise input fields are named in tff order.

Intel-Media-SDK/MediaSDK,Intel-Media-SDK/MediaSDK,Intel-Media-SDK/MediaSDK,Intel-Media-SDK/MediaSDK,Intel-Media-SDK/MediaSDK