floppy: don't write kernel-only members to FDRAWCMD ioctl output

Do not leak kernel-only floppy_raw_cmd structure members to userspace.
This includes the linked-list pointer and the pointer to the allocated
DMA space.

Signed-off-by: Matthew Daley <mattd@bugfuzz.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
static void floppy_off(unsigned int drive)
{
	unsigned long volatile delta;
	int fdc = FDC(drive);

	if (!(FDCS->dor & (0x10 << UNIT(drive))))
		return;

	del_timer(motor_off_timer + drive);

	/* make spindle stop in a position which minimizes spinup time
	 * next time */
	if (UDP->rps) {
		delta = jiffies - UDRS->first_read_date + HZ -
		    UDP->spindown_offset;
		delta = ((delta * UDP->rps) % HZ) / UDP->rps;
		motor_off_timer[drive].expires =
		    jiffies + UDP->spindown - delta;
	}
	add_timer(motor_off_timer + drive);
}

static void floppy_off(unsigned int drive)
{
	unsigned long volatile delta;
	int fdc = FDC(drive);

	if (!(FDCS->dor & (0x10 << UNIT(drive))))
		return;

	del_timer(motor_off_timer + drive);

	/* make spindle stop in a position which minimizes spinup time
	 * next time */
	if (UDP->rps) {
		delta = jiffies - UDRS->first_read_date + HZ -
		    UDP->spindown_offset;
		delta = ((delta * UDP->rps) % HZ) / UDP->rps;
		motor_off_timer[drive].expires =
		    jiffies + UDP->spindown - delta;
	}
	add_timer(motor_off_timer + drive);
}
