[libsigc++2/variadic_mem_fun2] bound_*_mem_functor: Use limit_reference_base instead of aliases.

[Murray Cumming <murrayc src gnome org>]

commit c7dd1ff372268a4301eaa42a46ab27e471d5e5e8
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat Mar 5 11:00:43 2016 +0100

    bound_*_mem_functor: Use limit_reference_base instead of aliases.
    
    Because it is now simple enough.

 sigc++/functors/macros/mem_fun.h.m4 |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/sigc++/functors/macros/mem_fun.h.m4 b/sigc++/functors/macros/mem_fun.h.m4
index 78780a0..9a07e53 100644
--- a/sigc++/functors/macros/mem_fun.h.m4
+++ b/sigc++/functors/macros/mem_fun.h.m4
@@ -51,7 +51,7 @@ define([BOUND_MEMBER_FUNCTOR],[dnl
 template<class T_return, class T_obj, class... T_arg>
 using bound_[$1]mem_functor =
   bound_mem_functor_base<
-    [$1]limit_reference<T_obj>,
+    limit_reference_base<$2 T_obj, $2 T_obj>,
     T_return (T_obj::*)(T_arg...) $2,
     T_return, T_obj, T_arg...>;
 ])