The bit accounting was broken when refactor portions of PVQ to use the
 aom_reader / aom_writer API because the daala_ec calls were using
 OD_ACCOUNTING instead of CONFIG_ACCOUNTING.
This fixes them so that bit accounting will still work with pvq while
 the full port to --enable-accounting is in review.

Change-Id: I99e6b6debc716f1a6780116d5602085f7a2bb827