ide-floppy: Use blk_rq_is_scsi()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: linux-ide@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>