ide: clean up timed out request handling

8f6205cd introduced a bug where a
timed out DMA request is never requeued and lost.
6072f749 fixed this by making
ide_dma_timeout_retry() requeue the request itself.  While the fix is
correct, it makes DMA and non-DMA paths asymmetric regarding how the
in flight request is requeued.

As long as hwif->rq is set, the IDE driver is assuming ownership of
the request and the request should either be completed or requeued
when clearing hwif->rq.  In the timeout path, the ide driver holds
onto the request as long as the recovery action (ie. reset) is in
progress and clears it after the state machine is stopped (ide_stopped
return), so the existing requeueing logic is correct.  The bug
occurred because ide_dma_timeout_retry() explicitly clears hwif->rq
without requeueing it.

ide_dma_timeout_retry() is called only by ide_timer_expiry() and
returns ide_started only when ide_error() would return it - ie. after
r...