kevm-pyk/__main__: correct variable names

Author: ehildenb

kevm-pyk/src/kevm_pyk/__main__.py

@@ -382,7 +382,7 @@ def prove_it(_id_and_cfg: Tuple[str, Tuple[KCFG, Path]]) -> bool:
                     result_state = minimize_term(result_state)
                 _LOGGER.error(f'Proof failed: {_cfg_id}\n{foundry.pretty_print(result_state)}')
         _write_cfg(_cfg, _cfg_path)
-        failure_nodes = cfg.frontier + cfg.stuck
+        failure_nodes = _cfg.frontier + _cfg.stuck
         return len(failure_nodes) == 0
 
     with ProcessPool(ncpus=workers) as process_pool: