IDE: sg chaining support

Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index f36ff59..04273d3 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -846,7 +846,8 @@
 	ide_hwif_t *hwif = drive->hwif;
 
 	hwif->nsect = hwif->nleft = rq->nr_sectors;
-	hwif->cursg = hwif->cursg_ofs = 0;
+	hwif->cursg_ofs = 0;
+	hwif->cursg = NULL;
 }
 
 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);