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/mips/au1xxx-ide.c b/drivers/ide/mips/au1xxx-ide.c
index aebde49..892d08f 100644
--- a/drivers/ide/mips/au1xxx-ide.c
+++ b/drivers/ide/mips/au1xxx-ide.c
@@ -296,7 +296,7 @@
 			cur_addr += tc;
 			cur_len -= tc;
 		}
-		sg++;
+		sg = sg_next(sg);
 		i--;
 	}