Avoid unnecessary recursive function calls (closes #10519)
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 802f45f..9fea0c9 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1871,7 +1871,7 @@
         tmpkey = make_new_set(&PyFrozenSet_Type, key);
         if (tmpkey == NULL)
             return -1;
-        rv = set_contains(so, tmpkey);
+        rv = set_contains_key(so, tmpkey);
         Py_DECREF(tmpkey);
     }
     return rv;
@@ -1936,7 +1936,7 @@
         tmpkey = make_new_set(&PyFrozenSet_Type, key);
         if (tmpkey == NULL)
             return NULL;
-        result = set_discard(so, tmpkey);
+        result = set_discard_key(so, tmpkey);
         Py_DECREF(tmpkey);
         return result;
     }