[libxml2] fix reference to STDOUT_FILENO on MSVC

[Daniel Veillard <veillard src gnome org>]

commit b8428a2a25e6b0aff8ca33dd3d34c5c38fdb8749
Author: Tay Ray Chuan <rctay89 gmail com>
Date:   Mon Jan 2 15:49:31 2012 +0800

    fix reference to STDOUT_FILENO on MSVC
    
    The Microsoft Visual C++ compiler doesn't have unistd.h and thus
    STDOUT_FILENO is undefined. Define it using stdio.h functions.

 testC14N.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/testC14N.c b/testC14N.c
index dc1a9a6..f735a29 100644
--- a/testC14N.c
+++ b/testC14N.c
@@ -13,7 +13,9 @@
 #include <string.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
-#endif
+#else
+#define STDOUT_FILENO fileno(stdout)
+#endif /* HAVE_UNISTD_H */
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif