sys-apps/diffutils: Restrict "test" feature

These tests always fail when building for devices so we don't want to
run them by default, even when dragged in as a test dependency.

BUG=None
TEST=None

Change-Id: Ia1faf913633994f19cc1e409841cf21a98157b1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/1862709
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Auto-Submit: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
1 file changed