fix the typo

python/paddle/fluid/framework.py

@@ -536,7 +536,7 @@ class Operator(object):
     OP_WITHOUT_KERNEL_SET = {
         'feed', 'fetch', 'save', 'load', 'recurrent', 'go',
         'rnn_memory_helper_grad', 'conditional_block', 'while', 'send', 'recv',
-        'listen_and_serv', 'parallel_do', 'save_combine', 'loadload_combine',
+        'listen_and_serv', 'parallel_do', 'save_combine', 'load_combine',
         'ncclInit', 'select', 'checkpoint_notify', 'gen_nccl_id'
     }