bpo-42500: Fix recursion in or after except (GH-23568)

* Use counter, rather boolean state when handling soft overflows.
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index f05b33a..b80d37d 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1181,7 +1181,6 @@
 sys_setrecursionlimit_impl(PyObject *module, int new_limit)
 /*[clinic end generated code: output=35e1c64754800ace input=b0f7a23393924af3]*/
 {
-    int mark;
     PyThreadState *tstate = _PyThreadState_GET();
 
     if (new_limit < 1) {
@@ -1199,8 +1198,7 @@
        Reject too low new limit if the current recursion depth is higher than
        the new low-water mark. Otherwise it may not be possible anymore to
        reset the overflowed flag to 0. */
-    mark = _Py_RecursionLimitLowerWaterMark(new_limit);
-    if (tstate->recursion_depth >= mark) {
+    if (tstate->recursion_depth >= new_limit) {
         _PyErr_Format(tstate, PyExc_RecursionError,
                       "cannot set the recursion limit to %i at "
                       "the recursion depth %i: the limit is too low",