ide: fix buggy code in ide_register_hw()

Relocating the index to come after finding the hwif pointer.

Signed-off-by: Peter Teoh <htmldeveloper@gmail.com>
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index fa16bc3..c2b7912 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -667,7 +667,6 @@
 
 	do {
 		hwif = ide_deprecated_find_port(hw->io_ports[IDE_DATA_OFFSET]);
-		index = hwif->index;
 		if (hwif)
 			goto found;
 		for (index = 0; index < MAX_HWIFS; index++)
@@ -675,6 +674,7 @@
 	} while (retry--);
 	return -1;
 found:
+	index = hwif->index;
 	if (hwif->present)
 		ide_unregister(index, 0, 1);
 	else if (!hwif->hold)