bpo-39008: Require Py_ssize_t for PySys_Audit formats rather than raise a deprecation warning (GH-17540)

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index b6bdf51..9f866a2 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -181,7 +181,7 @@
     if (argFormat && argFormat[0]) {
         va_list args;
         va_start(args, argFormat);
-        eventArgs = Py_VaBuildValue(argFormat, args);
+        eventArgs = _Py_VaBuildValue_SizeT(argFormat, args);
         va_end(args);
         if (eventArgs && !PyTuple_Check(eventArgs)) {
             PyObject *argTuple = PyTuple_Pack(1, eventArgs);