Remove no-longer-used RTE argument of markVarForSelectPriv().

In the wake of c028faf2a, this is no longer needed.  I left it
out of that patch since the API change would be undesirable in
a released branch; but there's no reason not to do it in HEAD.

src/backend/parser/parse_target.c

@@ -1397,7 +1397,7 @@ ExpandSingleTable(ParseState *pstate, ParseNamespaceItem *nsitem,
 		{
 			Var		   *var = (Var *) lfirst(l);
 
-			markVarForSelectPriv(pstate, var, rte);
+			markVarForSelectPriv(pstate, var);
 		}
 
 		return vars;