cashew: fix cpplint errors

This CL fixes cpplint errors introduced in recent commits:
- whitespace fixes
- make members of ProcfsByteCounter::netdev_stats struct uint64s instead
  of unsigned longs.

BUG=chromium-os:18082
TEST=run cpplint, run unit tests, sanity check on device

Change-Id: Id09668360832d0ba09470ee54711f2e0df3bd7f1
Reviewed-on: http://gerrit.chromium.org/gerrit/4608
Tested-by: Vince Laviano <vlaviano@chromium.org>
Reviewed-by: Jason Glasgow <jglasgow@chromium.org>