mesa: move #include of mtypes.h outside __cplusplus check

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

src/mesa/main/errors.h

@@ -38,14 +38,13 @@
 
 #include "compiler.h"
 #include "glheader.h"
+#include "mtypes.h"
 
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#include "mtypes.h"
-
 struct _glapi_table;
 
 extern void