neigh: Kill hh_cache->hh_output

It's just taking on one of two possible values, either
neigh_ops->output or dev_queue_xmit().  And this is purely depending
upon whether nud_state has NUD_CONNECTED set or not.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index a52bb74..bcf9bb5 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -427,9 +427,9 @@
 			      dst_metric(&r->dst, RTAX_RTTVAR)),
 			r->rt_key_tos,
 			-1,
-			(r->dst.neighbour ?
-			 (r->dst.neighbour->hh.hh_output ==
-			  dev_queue_xmit) : 0),
+			(r->dst.neighbour &&
+			 (r->dst.neighbour->nud_state & NUD_CONNECTED)) ?
+			   1 : 0,
 			r->rt_spec_dst, &len);
 
 		seq_printf(seq, "%*s\n", 127 - len, "");