Signed-off-by: wangxiaotao1980 <wangxiaotao1980@gmail.com>
bug no 471 Qiniu_Io_call 函数 memory leak,
Merge pull request #115 from wangxiaotao1980/hotfix/memleak

Signed-off-by: wangxiaotao1980 <wangxiaotao1980@gmail.com>