Revert "libata, freezer: avoid block device removal while system is frozen"

Revert "libata, freezer: avoid block device removal while system is frozen"

This reverts commit d3d507a2579b6bbc83ef90f59caaf84e9c7d1bd0.

The commit was added as a quick band-aid for a hang that happened when a
block device was removed during system suspend. Now that bdi_wq is not
freezable anymore the hang should not be possible and we can get rid of
this hack by reverting it.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>