ide: cleanup ide_setup_dma()

* There is no need to call ide_release_dma_engine().

* Move the code up to (and including) ide_allocate_dma_engine()
  call to the callers of ide_setup_dma().

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>