Also revert an incidental 'gofmt' of a vendored file from CL 205240.

Updates #34822

Change-Id: I82a015d865db4d865b4776a8013312f25dbb9181
Reviewed-on: https://go-review.googlesource.com/c/go/+/205539
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>