bug fix:   when a bucket is marked as transfer_out, cannot transfered by another client who's marked as transfer_in status when the bucket's status is not right. the same for transfer_in case.
bug fix:
  when a bucket is marked as transfer_out, cannot transfered by another client who's marked as transfer_in status when the bucket's status is not right. the same for transfer_in case.

zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17