Fix MSVC warning in sample programs
The warning was caused because of conversions from size_t to int, which
can cause data loss. The files affected are:
* ssl_client2.c
* ssl_server2.c
* ssl_mail_client.c
diff --git a/programs/ssl/ssl_mail_client.c b/programs/ssl/ssl_mail_client.c
index 27c57a1..8958f18 100644
--- a/programs/ssl/ssl_mail_client.c
+++ b/programs/ssl/ssl_mail_client.c
@@ -57,8 +57,8 @@
#include <unistd.h>
#else
#include <io.h>
-#define read _read
-#define write _write
+#define read(fd, buf, len) _read( fd, (void *)buf, (unsigned int)len )
+#define write(fd, buf, len) _write( fd, (const void *)buf, (unsigned int)len )
#endif
#if defined(_WIN32) || defined(_WIN32_WCE)