OSV-2020-1238 Use-of-uninitialized-value in pcpp::Packet::createFirstLayer

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22085 Crash type: Use-of-uninitialized-value Crash state: pcpp::Packet::createFirstLayer pcpp::Packet::setRawPacket FuzzTarget.cpp...