restore the previous idiom in callbacks.c

Author: neonene

Modules/_ctypes/callbacks.c

@@ -348,7 +348,11 @@ CThunkObject *_ctypes_alloc_callback(PyObject *callable,
     if (p == NULL) {
         return NULL;
     }
-    assert(CThunk_CheckExact(GLOBAL_STATE(), (PyObject *)p));
+
+#ifdef Py_DEBUG
+    ctypes_state *st = GLOBAL_STATE();
+    assert(CThunk_CheckExact(st, (PyObject *)p));
+#endif
 
     p->pcl_write = Py_ffi_closure_alloc(sizeof(ffi_closure), &p->pcl_exec);
     if (p->pcl_write == NULL) {