blk_end_request: changing ps3disk (take 4)

This patch converts ps3disk to use blk_end_request interfaces.
Related 'uptodate' arguments are converted to 'error'.

Cc: Geoff Levand <geoffrey.levand@am.sony.com>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>