checkperms: update to handle autoconf more generally
checkperms: update to handle autoconf more generally

Fixes recent libxml change.  Simplifies code a bit.

Review URL: http://codereview.chromium.org/3028008

git-svn-id: http://src.chromium.org/svn/trunk/src@52768 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 3ab4f454721883977bb2c581ee318184cd2b617f
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser