atp870u: Fix incorrect writeb_io access to register 0x3a

The ioport region is 0x20 bytes long so accessing 0x3a register using
writeb_io is incorrect. Use writeb_base instead.
There's no change in behavior as 870 chips have ioport = baseport.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/atp870u.c

@@ -364,9 +364,9 @@ static irqreturn_t atp870u_intr_handle(int irq, void *dev_id)
 					atp_writeb_base(dev, 0x3b, atp_readb_base(dev, 0x3b) & 0x3f);
 			} else {				
 				if ((workreq->cmnd[0] == 0x08) || (workreq->cmnd[0] == 0x28) || (workreq->cmnd[0] == 0x0a) || (workreq->cmnd[0] == 0x2a))
-					atp_writeb_io(dev, c, 0x3a, (atp_readb_io(dev, c, 0x3a) & 0xf3) | 0x08);
+					atp_writeb_base(dev, 0x3a, (atp_readb_base(dev, 0x3a) & 0xf3) | 0x08);
 				else
-					atp_writeb_io(dev, c, 0x3a, atp_readb_io(dev, c, 0x3a) & 0xf3);
+					atp_writeb_base(dev, 0x3a, atp_readb_base(dev, 0x3a) & 0xf3);
 			}	
 			j = 0;
 			id = 1;
@@ -889,9 +889,9 @@ static void send_s870(struct atp_unit *dev,unsigned char c)
 			atp_writeb_base(dev, 0x3b, atp_readb_base(dev, 0x3b) & 0x3f);
 	} else {		
 		if ((workreq->cmnd[0] == 0x08) || (workreq->cmnd[0] == 0x28) || (workreq->cmnd[0] == 0x0a) || (workreq->cmnd[0] == 0x2a))
-			atp_writeb_io(dev, c, 0x3a, (atp_readb_io(dev, c, 0x3a) & 0xf3) | 0x08);
+			atp_writeb_base(dev, 0x3a, (atp_readb_base(dev, 0x3a) & 0xf3) | 0x08);
 		else
-			atp_writeb_io(dev, c, 0x3a, atp_readb_io(dev, c, 0x3a) & 0xf3);
+			atp_writeb_base(dev, 0x3a, atp_readb_base(dev, 0x3a) & 0xf3);
 	}	
 
 	if(workreq->sc_data_direction == DMA_TO_DEVICE) {