Open code the parts of map_swap_entry that was actually used by
swapdev_block, and remove the now unused map_swap_entry function.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>