Defines starting with `m' in bsd/netinet

• MAX_IPOPTLEN bsd/netinet/ip_var.h:122
• MAX_TCPOPTLEN bsd/netinet/tcp_output.c:104
• MAXTTL bsd/netinet/ip.h:188
• MAXVIFS bsd/netinet/ip_mroute.h:93
• MRTHASHSIZ bsd/netinet/ip_mroute.h:173