vfwcap: Include windows.h before vfw.h since the latter requires defines

from the former.
Patch by kemuri <kemuri9 at gmail dot com>

Originally committed as revision 21411 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavdevice/vfwcap.c

@@ -20,8 +20,8 @@
  */
 
 #include "libavformat/avformat.h"
-#include <vfw.h>
 #include <windows.h>
+#include <vfw.h>
 
 //#define DEBUG_VFW