Fix type of _buflen
Fix type of _buflen

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