Refactoring: Remove unnecessary logic from push_to_trunk.

Remove some svnish things that are output-only.

BUG=chromium:410721
LOG=n
TBR=tandrii@chromium.org

Review URL: https://codereview.chromium.org/598403003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24231 ce2b1a6d-e550-0410-aec6-3dcde31c8c00