nd6: zap dead store nd6_allocated

[Klemens Nanni]

There since KAME IPv6 import in 1999.

OK?

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index df6cf601b34..ff679bcb151 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -86,7 +86,7 @@ int nd6_debug = 0;
 
 TAILQ_HEAD(llinfo_nd6_head, llinfo_nd6) nd6_list;
 struct pool nd6_pool;          /* pool for llinfo_nd6 structures */
-int    nd6_inuse, nd6_allocated;
+int    nd6_inuse;
 
 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
 
@@ -885,7 +885,6 @@ nd6_rtrequest(struct ifnet *ifp, int req, struct rtentry 
*rt)
                        break;
                }
                nd6_inuse++;
-               nd6_allocated++;
                ln->ln_rt = rt;
                /* this is required for "ndp" command. - shin */
                if (req == RTM_ADD) {