util/ralloc: Fix extern "C" usage.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/util/ralloc.h

@@ -46,16 +46,16 @@
 #ifndef RALLOC_H
 #define RALLOC_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include <stddef.h>
 #include <stdarg.h>
 #include <stdbool.h>
 
 #include "macros.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \def ralloc(ctx, type)
  * Allocate a new object chained off of the given context.