.map function of dm-delay returns return value of delay_bio(),
hence it's supposed to return using a defined DM_MAPIO macro.
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Acked-By: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>