MFH: r560305

net/ns3: fix build on GCC architectures

../src/test/ns3tc/fq-codel-queue-disc-test-suite.cc:555:125: error: 'u_int32_t' has not been declared

555 | FqCoDelQueueDiscECNMarking::AddPacket (Ptr<FqCoDelQueueDisc> queue, Ipv4Header hdr, u_int32_t nPkt, u_int32_t nPktEnqueued, u_int32_t nQueueFlows)