cmd/toolstash: adapt to golang.org/x/tools

This repo already contains an identical LICENSE.
The README adds little, particularly in golang.org/x.
Update the custom import path comment.

Change-Id: I23fb5e31df6ff4828d298d44dc30dca901b0627b
Reviewed-on: https://go-review.googlesource.com/32682
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
3 files changed