fsstress: allow afsync on directories too

Currently the afsync function can only be performed against regular files.
Allow it to operate on directories too, to increase test coverage and
allow for chances of finding bugs in a filesystem's implementation of
fsync against directories.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
1 file changed