Fix BfsFileImpl::Close timeout
Fix BfsFileImpl::Close timeout

yvxiang/coverage_for_bfs,bluebore/dfs,yvxiang/dfs,bluebore/bfs,00k/ToyDFS,lylei/dfs,yvxiang/coverage_for_bfs,baidu/bfs,baidu/bfs,linyvxiang/dfs,yvxiang/dfs,baidu/bfs,linyvxiang/dfs,myawan/bfs-1,lylei/dfs,myawan/bfs-1,bluebore/bfs,00k/ToyDFS,lylei/dfs,bluebore/dfs,myawan/bfs-1,bluebore/dfs,linyvxiang/dfs,yvxiang/coverage_for_bfs,baidu/bfs,bluebore/bfs,yvxiang/dfs,yvxiang/dfs,myawan/bfs-1,lylei/dfs,yvxiang/coverage_for_bfs