The code reading these variables was removed in CL 41476. They are only
set but never read now, so remove them.

Change-Id: I6b0b8d813e9a3ec2a13586ff92746e00ad1b5bf0
Reviewed-on: https://go-review.googlesource.com/106095
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>