Minor perf improvements to software transform

About 4% improvement in Crisis Core with hardware transform off.  Won't help many games much but I remember there were a few games that spent a bit of time there (can't remember which ones, most likely 2d ones.)

The SSE usage in general is really a lot better in software transform, I thought the compiler was doing a bad job in softgpu's code but I guess it just wasn't lending itself as well to it or something.

-[Unknown]