CLEANUP: hlua: use hlua_pusherror() where relevant

In hlua_map_new(), when error occurs we use a combination of luaL_where,
lua_pushfstring and lua_concat to build the error string before calling
lua_error().

It turns out that we already have the hlua_pusherror() macro which is
exactly made for that purpose so let's use it.

It could be backported to all stable versions to ease code maintenance.

(cherry picked from commit 6e48499)
Signed-off-by: Amaury Denoyelle <[email protected]>

Author: Darlelet

src/hlua.c

@@ -2369,9 +2369,7 @@ __LJMP static int hlua_map_new(struct lua_State *L)
 		/* error case: we can't use luaL_error because we must
 		 * free the err variable.
 		 */
-		luaL_where(L, 1);
-		lua_pushfstring(L, "'new': %s.", err);
-		lua_concat(L, 2);
+		hlua_pusherror(L, "'new': %s.", err);
 		free(err);
 		chunk_destroy(&args[0].data.str);
 		WILL_LJMP(lua_error(L));