Make snprintf() and vsnprintf() conform to C99.

winsup/mingw/mingwex/stdio/snprintf.c

@@ -1,13 +0,0 @@
-#include <stdarg.h>
-#include <stdio.h>
-
-int snprintf(char* buffer, size_t n, const char* format, ...)
-{
-  int retval;
-  va_list argptr;
-         
-  va_start( argptr, format );
-  retval = _vsnprintf( buffer, n, format, argptr );
-  va_end( argptr );
-  return retval;
-}