OSV-2020-1383 Container-overflow in grk::T2Decode::read_packet_header

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=24427 Crash type: Container-overflow READ 8 Crash state: grk::T2Decode::readpacketheader grk::T2Decode::decodepacket grk::T2Decode::decodepackets...