sys-apps/util-linux: upgrade to 2.28.2

This CL imports util-linux 2.28.2 from upstream Gentoo with the ebuild
modified as follows:
- KEYWORDS is changed to "*"
- python3_6 is removed from PYTHON_COMPAT (as python-utils-r1.eclass
  in Chrome OS doesn't yet know about python3_6)

BUG=chromium:721785
TEST=Remote trybot runs.

Change-Id: I460c5eff9171f740cea600e01110f6244e6a171e
Reviewed-on: https://chromium-review.googlesource.com/503495
Commit-Ready: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
4 files changed