generic/062, 520: Don't remove lost+found during cleanup

generic/062, 520: Don't remove lost+found during cleanup

On older e2fsprogs, fsck command will check lost+found for extX,
so that it will get error if lost+found has been removed during
cleanup.  For example:
----------------------------------------------------------
e2fsck 1.41.12 (17-May-2010)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
/lost+found not found.  Create? no
...
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Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>