The loopback driver failed to emit the change uevent when auto releasing
the device.  Fixed lo_release() to pass the bdev to loop_clr_fd() so it
can emit the event.
Signed-off-by: NPhillip Susi <psusi@cfl.rr.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ayan George <ayan@ayan.net>
Signed-off-by: NAndrew Morton <akpm@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>