This patch converts xsysace to use blk_end_request().
xsysace is a little bit different from "normal" drivers.
xsysace driver has a state machine in it.
It calls end_that_request_first() and end_that_request_last()
from different states. (ACE_FSM_STATE_REQ_TRANSFER and
ACE_FSM_STATE_REQ_COMPLETE, respectively.)
However, those states are consecutive and without any interruption
inbetween.
So we can just follow the standard conversion rule (b) mentioned in
the patch subject "[PATCH 01/27] blk_end_request: add new request
completion interface".