ide: cleanup rq->data_len usages

With recent unification of fields, it's now guaranteed that
rq->data_len always equals blk_rq_bytes().  Convert all direct users
to accessors.

[ Impact: convert direct rq->data_len usages to blk_rq_bytes() ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.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 59799ca..ca2519d 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -116,7 +116,7 @@
 unsigned int ide_rq_bytes(struct request *rq)
 {
 	if (blk_pc_request(rq))
-		return rq->data_len;
+		return blk_rq_bytes(rq);
 	else
 		return blk_rq_cur_sectors(rq) << 9;
 }