ata_bus_softreset() should return AC_ERR_* on failure not arbitrary
positive number.  While at it, reformat comment above it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>