For some reason, contrib/traceroute/traceroute.c ensures MAXHOSTNAMELEN

is defined, but then proceeds to use a hardcoded maximum hostname length
of 64 anyway.  Fix this by checking against MAXHOSTNAMELEN instead.

PR:		bin/157732
MFC after:	3 days

contrib/traceroute/traceroute.c

@@ -1618,7 +1618,7 @@ gethostinfo(register char *hostname)
 	register char **p;
 	register u_int32_t addr, *ap;
 
-	if (strlen(hostname) > 64) {
+	if (strlen(hostname) >= MAXHOSTNAMELEN) {
 		Fprintf(stderr, "%s: hostname \"%.32s...\" is too long\n",
 		    prog, hostname);
 		exit(1);