[IPV6] ROUTE: Try to use router which is not known unreachable.

Only routers in "FAILED" state should be considered unreachable.
Otherwise, we do not try to use speicific routes unless all least specific
routers are considered unreachable.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index c953466..5132821 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -330,6 +330,8 @@
 		read_lock_bh(&neigh->lock);
 		if (neigh->nud_state & NUD_VALID)
 			m = 2;
+		else if (!(neigh->nud_state & NUD_FAILED))
+			m = 1;
 		read_unlock_bh(&neigh->lock);
 	}
 	return m;