all: remove redundant words in comment

all: remove redundant words in comment

Change-Id: I8e6be76f24a7b1bb21cc244d5117fa60efff03b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/703317
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: Than McIntosh <thanm@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Auto-Submit: Emmanuel Odeke <emmanuel@orijtech.com>