Improve softgpu performance a bit more

And small tweaks to logging of rel2 relocations, since I was looking at them to see if they make/don't make sense for GE2.

Anyway, these changes (especially the GetPixelDataOffset one) improve performance by roughly 14%, which is half what bilinear filtering cost (a price I gladly pay.)  Anyway, it makes up for it a bit.

-[Unknown]