umc8672: don't use ide_hwifs[] in umc_set_pio_mode()

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/legacy/umc8672.c

@@ -105,13 +105,13 @@ static void umc_set_speeds (u8 speeds[])
 
 static void umc_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
+	ide_hwif_t *hwif = drive->hwif;
 	unsigned long flags;
-	ide_hwgroup_t *hwgroup = ide_hwifs[HWIF(drive)->index^1].hwgroup;
 
 	printk("%s: setting umc8672 to PIO mode%d (speed %d)\n",
 		drive->name, pio, pio_to_umc[pio]);
 	spin_lock_irqsave(&ide_lock, flags);
-	if (hwgroup && hwgroup->handler != NULL) {
+	if (hwif->mate && hwif->mate->hwgroup->handler) {
 		printk(KERN_ERR "umc8672: other interface is busy: exiting tune_umc()\n");
 	} else {
 		current_speeds[drive->name[2] - 'a'] = pio_to_umc[pio];