Variables starting with `z' in BSD4-4

• zdmap sys/dmap.h:51
• zeroin_addr netinet/in_pcb.c:58
• zeroiso_addr netiso/iso_pcb.c:97
• zerons_addr netns/ns_pcb.c:51
• zmk netiso/iso_snpac.c:104
• zombproc sys/proc.h:230