Document net.inet.tcp.syncookies_only using a description taken from tcp_syncache.c revision 1.99 of andre's commit log.
Document net.inet.tcp.syncookies_only using a description taken from
tcp_syncache.c revision 1.99 of andre's commit log.

PR:	107611

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase