locale.c: Use proper macro

querylocale_c()  likely will expand to the correct thing, but it isn't
defined until higher in the stack of locale handling layers.  Instead
use the construct that is lower in the stack.

locale.c

@@ -1484,7 +1484,8 @@ S_stdize_locale(pTHX_ const int category,
             retval = input_locale;  /* The input can be returned unchanged */
         }
         else {
-            retval = save_to_buffer(querylocale_c(LC_ALL), buf, buf_size);
+            retval = save_to_buffer(posix_setlocale(LC_ALL, NULL),
+                                    buf, buf_size);
         }
 
         for (i = 0; i < LC_ALL_INDEX_; i++) {