review: remove redundant todos
review: remove redundant todos

Change-Id: I2b96d20ad2ab925fbda2b13db85360c357b83e0b
Reviewed-on: https://go-review.googlesource.com/1700
Reviewed-by: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

Go-zh/review,golang/review