rtree memory leak patch

Here is a patch for a memory leak in rtree.c, version 7.2.1 (in code
that I submitted last year, alas).

Ken

*** postgresql-7.2.1/src/backend/access/rtree/rtree.c.orig      Thu May
23 22:24:47 2002
--- postgresql-7.2.1/src/backend/access/rtree/rtree.c   Fri May 24
09:25:17 2002
***************
*** 931,936 ****
--- 931,938 ----

PointerGetDatum(&size_alpha));
                         FunctionCall2(&rtstate->sizeFn, union_dr,

PointerGetDatum(&size_beta));
+                       pfree(DatumGetPointer(union_dl));
+                       pfree(DatumGetPointer(union_dr));

                         diff = (size_alpha - size_l) - (size_beta -
size_r);