Fix compilation on mingw.

Patch by: cjacek

http://codereview.chromium.org/6024011


git-svn-id: http://ots.googlecode.com/svn/trunk@45 a4e77c2c-9104-11de-800e-5b313e0d2bf3
diff --git a/include/opentype-sanitiser.h b/include/opentype-sanitiser.h
index 6cba8cf..63bf65f 100644
--- a/include/opentype-sanitiser.h
+++ b/include/opentype-sanitiser.h
@@ -5,7 +5,7 @@
 #ifndef OPENTYPE_SANITISER_H_
 #define OPENTYPE_SANITISER_H_
 
-#if defined(_MSC_VER)
+#if defined(_WIN32)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;
 typedef short int16_t;
@@ -14,7 +14,7 @@
 typedef unsigned int uint32_t;
 typedef __int64 int64_t;
 typedef unsigned __int64 uint64_t;
-#include <Winsock2.h>  // for htons/ntohs
+#include <winsock2.h>  // for htons/ntohs
 #else
 #include <arpa/inet.h>
 #include <stdint.h>