build_packages: Remove experimental goma wrapper

Goma doesn't improve build_packages performance currently, so remove the
experimental code for this feature from build_packages.

BUG=chromium:926963
TEST=None

Change-Id: I7d36bef2b88e3b3ede98a24c948643c81816583a
Reviewed-on: https://chromium-review.googlesource.com/1749476
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Commit-Ready: Chris McDonald <cjmcdonald@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed