internal/copyright: skip testdata and vendor directories only
Using filepath.SkipDir without confirming that d is a directory makes
it prone to taking unintended action if a file (not a directory) with
the same name gets added.
This isn't a problem today, but we shouldn't spend human code review
time checking that this doesn't somehow happen in the future, either.
Change-Id: I29bf203ddef175c3ad23c9ddc10fa934126ac853
Reviewed-on: https://go-review.googlesource.com/c/go/+/630635 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Bypass: Dmitri Shuralyov <dmitshur@golang.org>