test: gofmt bounds.go

Change-Id: I8b462e20064658120afc8eb1cbac926254d1e24e
Reviewed-on: https://go-review.googlesource.com/114937
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>