Remove spurious NULL in descrobject.c (GH-20344)

Co-authored-by: hai shi <shihai1991@126.com>
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index c29cf7a..fce9cdd 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -360,7 +360,6 @@
     if (method_check_args(func, args, nargs, NULL)) {
         return NULL;
     }
-     NULL;
     PyCMethod meth = (PyCMethod) method_enter_call(tstate, func);
     if (meth == NULL) {
         return NULL;