According to the readdir(2) man-page, not all file-systems support returning the
entry's file-type in `d_type`. For example, the reprotest reproducibility tool,
uses the disorderfs FUSE file-system to shuffle the order in which directory
entries are returned, and this does not set `d_type`. Therefore, in addition to
entries with type `DT_DIR` and `DT_LNK`, also process entries with type
`DT_UNKNOWN`.
Signed-off-by: Jeremy Sowden <azazel@debian.org>
