[babl] Use _WIN32 instead of WIN32

[Tor Lillqvist <tml src gnome org>]

commit 0f38fb3618483bba37ab33abae53691322193776
Author: Tor Lillqvist <tml iki fi>
Date:   Fri Jan 29 11:56:24 2010 +0200

    Use _WIN32 instead of WIN32

 babl/babl-mutex.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/babl/babl-mutex.h b/babl/babl-mutex.h
index 1636da3..99fdbaa 100644
--- a/babl/babl-mutex.h
+++ b/babl/babl-mutex.h
@@ -19,14 +19,14 @@
 #ifndef _BABL_MUTEX_H
 #define _BABL_MUTEX_H
 
-#ifndef WIN32
+#ifndef _WIN32
 #define __USE_GNU 1
 #include <pthread.h>
 #else
 #include <windows.h>
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
   typedef  CRITICAL_SECTION   BablMutex;
 #else
   typedef  pthread_mutex_t   BablMutex;