Defines starting with `r' in bsd/netinet

• REDUCE bsd/netinet/in_cksum.c:127
• RIPRCVQ bsd/netinet/raw_ip.c:86
• RIPSNDQ bsd/netinet/raw_ip.c:85
• rt_expire bsd/netinet/if_ether.c:109
• RTF_ANNOUNCE bsd/netinet/if_ether.h:174
• RTF_USETRAILERS bsd/netinet/if_ether.h:173