[patch] some PQExpBuffer are not destroyed in pg_dump

Hi al

In getDefaultACLs function, some PQExpBuffer are not destroy

File: src/bin/pg_dump/pg_dump.c
DefaultACLInfo *
getDefaultACLs(Archive *fout, int *numDefaultACLs)
{
......
if (fout->remoteVersion >= 90600)
{
PQExpBuffer acl_subquery = createPQExpBuffer(); // *** acl_subquery not destroyed ***
PQExpBuffer racl_subquery = createPQExpBuffer(); // *** racl_subquery not destroyed ***
PQExpBuffer initacl_subquery = createPQExpBuffer(); // *** initacl_subquery not destroyed ***
PQExpBuffer initracl_subquery = createPQExpBuffer(); // *** initracl_subquery not destroyed ***

buildACLQueries(acl_subquery, racl_subquery, initacl_subquery,
initracl_subquery, "defaclacl", "defaclrole",
"CASE WHEN defaclobjtype = 'S' THEN 's' ELSE defaclobjtype END::\"char\"",
dopt->binary_upgrade);

appendPQExpBuffer(query, "SELECT d.oid, d.tableoid, "
"(%s d.defaclrole) AS defaclrole, "
"d.defaclnamespace, "
"d.defaclobjtype, "
"%s AS defaclacl, "
"%s AS rdefaclacl, "
"%s AS initdefaclacl, "
"%s AS initrdefaclacl "
"FROM pg_default_acl d "
"LEFT JOIN pg_init_privs pip ON "
"(d.oid = pip.objoid "
"AND pip.classoid = 'pg_default_acl'::regclass "
"AND pip.objsubid = 0) ",
username_subquery,
acl_subquery->data,
racl_subquery->data,
initacl_subquery->data,
initracl_subquery->data);
}
......

Here is a patch.

Best Regards!