bgpd: Partially revert f018db8, fixes BZ#730

  The change from bgp_node_get() to bgp_node_lookup() broke aggregation.

Signed-off-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
Tested-by: Martin Winter <mwinter@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index cd8f3fe..0337224 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -4678,9 +4678,7 @@
   if (BGP_INFO_HOLDDOWN (ri))
     return;
 
-  child = bgp_node_lookup (table, p);
-  if (! child)
-    return;
+  child = bgp_node_get (table, p);
 
   /* Aggregate address configuration check. */
   for (rn = child; rn; rn = rn->parent)
@@ -4714,9 +4712,7 @@
   if (p->prefixlen == 0)
     return;
 
-  child = bgp_node_lookup (table, p);
-  if (! child)
-    return;
+  child = bgp_node_get (table, p);
 
   /* Aggregate address configuration check. */
   for (rn = child; rn; rn = rn->parent)