ide-pmac: fix pmac_ide_init_hwif_ports()

* pmac_ide_init_hwif_ports() can be called by ide_init_hwif_ports()
  (through ppc_ide_md.ide_init_hwif hook) for non IDE PMAC interfaces.
  If this is the case the hw->io_ports[] should be already setup by
  ide_init_hwif_ports()->ide_std_init_ports() so remove redundant code
  from pmac_ide_init_hwif_ports().

  As side-effect this change fixes ctl_addr == 0 special handling in
  ide_init_hwif_ports().

* Fix misleading comment while at it.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ppc/pmac.c b/drivers/ide/ppc/pmac.c
index 7f7a598..4559e29 100644
--- a/drivers/ide/ppc/pmac.c
+++ b/drivers/ide/ppc/pmac.c
@@ -438,13 +438,8 @@
 		if (data_port == pmac_ide[ix].regbase)
 			break;
 
-	if (ix >= MAX_HWIFS) {
-		/* Probably a PCI interface... */
-		for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; ++i)
-			hw->io_ports[i] = data_port + i - IDE_DATA_OFFSET;
-		hw->io_ports[IDE_CONTROL_OFFSET] = ctrl_port;
-		return;
-	}
+	if (ix >= MAX_HWIFS)
+		return;		/* not an IDE PMAC interface */
 
 	for (i = 0; i < 8; ++i)
 		hw->io_ports[i] = data_port + i * 0x10;