sc1200: fix ->dma_base equal zero handling

Set hwif->atapi_dma/{ultra,mwdma}_mask and drive->autodma after checking that
->dma_base exists.  If ->dma_base is not set (== PCI BAR4 cannot be reserved)
then DMA hooks shouldn't be initialized or bad things will happen.

OTOH hwif->set_{pio,dma}_mode hooks should be set even if hwif->dma_base == 0.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/pci/sc1200.c

@@ -378,16 +378,20 @@ static void __devinit init_hwif_sc1200 (ide_hwif_t *hwif)
 	if (hwif->mate)
 		hwif->serialized = hwif->mate->serialized = 1;
 	hwif->autodma = 0;
-	if (hwif->dma_base) {
+
+	hwif->set_pio_mode = &sc1200_set_pio_mode;
+	hwif->set_dma_mode = &sc1200_set_dma_mode;
+
+	if (hwif->dma_base == 0)
+		return;
+
 	hwif->udma_filter = sc1200_udma_filter;
 	hwif->ide_dma_check = &sc1200_config_dma;
 	hwif->ide_dma_end   = &sc1200_ide_dma_end;
+
 	if (!noautodma)
 		hwif->autodma = 1;
 
-		hwif->set_pio_mode = &sc1200_set_pio_mode;
-		hwif->set_dma_mode = &sc1200_set_dma_mode;
-	}
         hwif->atapi_dma = 1;
         hwif->ultra_mask = 0x07;
         hwif->mwdma_mask = 0x07;