math/f32, math/f64: add a comment that "Aff" stands for affine
transformation.

Change-Id: Ia5762d0578f78b17d85f4a952b397a05e6927bd0
Reviewed-on: https://go-review.googlesource.com/6914
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2 files changed