* in floppy drivers and ps2esdi - replaced with use of ->rq_disk;
floppy drivers already have information about "type" part of device number
- they had stored that information in floppy_open(), so all we need is a
"which drive" part.  And that is available from ->rq_disk.
	* DAC960: changed ->private_data initialization - instead of pointing
it to controller (which we already have as disk->queue.queuedata) we simply
store a disk number in there.  That had simplified ->revalidate_disk() and
allowed to kill the use of ->rq_dev in request handler.