all: fix some vet warnings

Change-Id: I85c2912a6862c6c251450f2a0926ecd33a9fb8e7
Reviewed-on: https://go-review.googlesource.com/34815
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
1 file changed