FTransformWHT optimization.
FTransformWHT optimization.

Data is packed sooner in the functions.

Change-Id: I018cfeca43f015ac755c7f209f9a97984cc0517b

webmproject/libwebp,PKRoma/libwebp,webmproject/libwebp,webmproject/libwebp,PKRoma/libwebp,webmproject/libwebp,PKRoma/libwebp,PKRoma/libwebp,PKRoma/libwebp,webmproject/libwebp,PKRoma/libwebp