deapexer: remove lost+found directory

`deapexer extract` which uses `rdump` command of `debugfs` creates
`lost+found` directory as well. Because the directory is not necessary,
remove it after extraction.

Bug: 159711661
Test: deapexer extract <apex> <dir>
      <dir> should not contain lost+found directory
Change-Id: I77800cb121371b796b940b5792dd16ced41da0fa
1 file changed