OSV-2020-1237 Use-of-uninitialized-value in pcpp::NullLoopbackLayer::getFamily

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22084 Crash type: Use-of-uninitialized-value Crash state: pcpp::NullLoopbackLayer::getFamily pcpp::NullLoopbackLayer::parseNextLayer pcpp::Packet::setRawPacket...