amd74xx/via82cxxx: don't initialize drive->dn

drive->dn is initialized by ide-probe.c::probe_hwif() so no need to do it
in ->init_hwif method.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/pci/amd74xx.c

@@ -383,7 +383,6 @@ static void __devinit init_hwif_amd74xx(ide_hwif_t *hwif)
 		hwif->drives[i].io_32bit = 1;
 		hwif->drives[i].unmask = 1;
 		hwif->drives[i].autotune = 1;
-		hwif->drives[i].dn = hwif->channel * 2 + i;
 	}
 
 	if (!hwif->dma_base)

drivers/ide/pci/via82cxxx.c

@@ -438,7 +438,6 @@ static void __devinit init_hwif_via82cxxx(ide_hwif_t *hwif)
 		hwif->drives[i].io_32bit = 1;
 		hwif->drives[i].unmask = (vdev->via_config->flags & VIA_NO_UNMASK) ? 0 : 1;
 		hwif->drives[i].autotune = 1;
-		hwif->drives[i].dn = hwif->channel * 2 + i;
 	}
 
 	if (!hwif->dma_base)