bgpd: unlock node on aggregate error

* bgp_route.c: (bgp_aggregate_set) make sure to unlock BGP node if failure
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 85526f5..8b0a3bf 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -5059,11 +5059,12 @@
   if (rn->info)
     {
       vty_out (vty, "There is already same aggregate network.%s", VTY_NEWLINE);
-      /* remove  old entry */
+      /* try to remove the old entry */
       ret = bgp_aggregate_unset (vty, prefix_str, afi, safi);
       if (ret)
         {
-          vty_out (vty, "Error deleteing aggregate%s", VTY_NEWLINE);
+          vty_out (vty, "Error deleting aggregate.%s", VTY_NEWLINE);
+	  bgp_unlock_node (rn);
 	  return CMD_WARNING;
         }
     }