network: Don't report deletion of cloned routes
ARP and ND6 expiration works around one big timer vs timers
per address. As such, when expiry happens a flood of RTM_DELETE
messages can easily overflow the route(4) socket.
Now that RTM_MISS is reported for any unresolvable address via
these protocols, the reporting of the address expiring or being
maually deleted becomes questionable for any use cases pertaining
to it.
If we do want to report this in the future, we should move to
per address timers rather than one big timer.
UnifiedSplitRaw
