ospfd: add missing unlock for ospf_interface_address_delete()

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Acked-by: Feng Lu <lu.feng@6wind.com>
diff --git a/ospfd/ospf_zebra.c b/ospfd/ospf_zebra.c
index fe1f45d..2704100 100644
--- a/ospfd/ospf_zebra.c
+++ b/ospfd/ospf_zebra.c
@@ -312,6 +312,7 @@
 
   assert (rn->info);
   oi = rn->info;
+  route_unlock_node (rn);
 
   /* Call interface hook functions to clean up */
   ospf_if_free (oi);