Count the size of the directories when calculating the size in DirInfo

[hedonihilist]

I noticed that the size and blocks in DirInfo struct only take account of the sizes and blocks of files in that directory(recursively), which resulting in the inaccuracy output of du command. Since the directories do take actual disk space, I guess it will make more sense if we take the size of sub-directories into consideration when calculating the size in DirInfo.

[sophiajt]

Nice catch