fix the bug in RTDiskPostingReader::decodeTo(), in which decodedDocCount was not correct.
fix the bug in RTDiskPostingReader::decodeTo(), in which decodedDocCount was not correct.

izenecloud/izenelib,izenecloud/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib