spec: fix typo in example comment
spec: fix typo in example comment

R=rsc, golang-dev
CC=golang-dev
http://codereview.appspot.com/5475046

Committer: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go