scsi: fix resid_len mis-conversion in scsi_end_request()

Commit c3a4d78c58 introduced
rq->data_len and converted residual count users to it.  While
converting, it mistakenly converted scsi_end_request() to finish
requests with residual count when it wants to do is fully complete the
request.  Fix it by using blk_end_request_all() instead.

This bug was spotted by Boaz Harrosh.

Signed-off-by: Tejun Heo <tj@kernel.org>
Spotted-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

drivers/scsi/scsi_lib.c

@@ -546,14 +546,9 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
 	 * to queue the remainder of them.
 	 */
 	if (blk_end_request(req, error, bytes)) {
-		int leftover = blk_rq_bytes(req);
-
-		if (blk_pc_request(req))
-			leftover = req->resid_len;
-
 		/* kill remainder if no retrys */
 		if (error && scsi_noretry_cmd(cmd))
-			blk_end_request(req, error, leftover);
+			blk_end_request_all(req, error);
 		else {
 			if (requeue) {
 				/*