dm delay: Use DM_MAPIO macros instead of open-coded equivalents
dm delay: Use DM_MAPIO macros instead of open-coded equivalents

.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 <b3dbb467a2790817398bcb77cb340b1133225387@gmail.com>
Acked-By: Mikulas Patocka <52f8f9962b7f38d8269c63c0859d68147c8d10f0@redhat.com>
Signed-off-by: Mike Snitzer <85e533f2e78486213c4d69f71462342ec0c62734@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs