ospf6d: convert LSDB to use route_node, improve performance

the performance in the presence of a large number of LSAs. I also verified
that the performance improvements stayed in the presence of a large number
of peers (I tested upto 128).

Signed-off-by: Dinesh G Dutt <ddutt at cumulusnetworks.com>
Reviewed-by: Scott Feldman <sfeldma at cumulusnetworks.com>Summary:
Reviewed-by: James Li <jli at cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/ospf6d/ospf6_lsa.c b/ospf6d/ospf6_lsa.c
index db14731..592aad9 100644
--- a/ospf6d/ospf6_lsa.c
+++ b/ospf6d/ospf6_lsa.c
@@ -450,8 +450,6 @@
   vty_out (vty, "CheckSum: %#06hx Length: %hu%s",
            ntohs (lsa->header->checksum),
            ntohs (lsa->header->length), VNL);
-  vty_out (vty, "    Prev: %p This: %p Next: %p%s",
-           lsa->prev, lsa, lsa->next, VNL);
   vty_out (vty, "Flag: %x %s", lsa->flag, VNL);
   vty_out (vty, "Lock: %d %s", lsa->lock, VNL);
   vty_out (vty, "ReTx Count: %d%s", lsa->retrans_count, VNL);
@@ -586,6 +584,7 @@
   copy->received = lsa->received;
   copy->installed = lsa->installed;
   copy->lsdb = lsa->lsdb;
+  copy->rn = NULL;
 
   return copy;
 }