The example incorrectly used buildutil.TagsDoc identifier which does not
exist. It should be buildutil.TagsFlagDoc instead.
The issue was introduced in https://golang.org/cl/9172 when this code was
first written.
Also use more idiomatic style for Go comments, '//' followed by a space,
then tab (instead of skipping the space). Although both render correctly
in godoc, this form is more correct and consistent.
Change-Id: I3b3c9767fe313106a8ff81e7887f3241c5806b59
Reviewed-on: https://go-review.googlesource.com/16743
Reviewed-by: Alan Donovan <adonovan@google.com>
747ae2594e