libxml2: upgraded package to upstream

BUG=chromium:406548
TEST=`emerge-lumpy libxml2` works.

Change-Id: Ia9ab5c938d17205bd67e2e51bed94ec796814931
Previous-Reviewed-on: https://chromium-review.googlesource.com/214262
(cherry picked from commit 1f26928fa523bad47e562492eb351214c251d6b1)
Reviewed-on: https://chromium-review.googlesource.com/216193
Reviewed-by: David Zeuthen <zeuthen@chromium.org>
Commit-Queue: David Zeuthen <zeuthen@chromium.org>
Tested-by: David Zeuthen <zeuthen@chromium.org>
6 files changed