[SCSI] add residual argument to scsi_execute and scsi_execute_req

scsi_execute() and scsi_execute_req() discard the residual length
information. Some callers need it. This adds residual argument
(optional) to scsi_execute and scsi_execute_req.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c
index ae87d08..d92ff51 100644
--- a/drivers/scsi/sr_ioctl.c
+++ b/drivers/scsi/sr_ioctl.c
@@ -207,7 +207,7 @@
 	memset(sense, 0, sizeof(*sense));
 	result = scsi_execute(SDev, cgc->cmd, cgc->data_direction,
 			      cgc->buffer, cgc->buflen, (char *)sense,
-			      cgc->timeout, IOCTL_RETRIES, 0);
+			      cgc->timeout, IOCTL_RETRIES, 0, NULL);
 
 	scsi_normalize_sense((char *)sense, sizeof(*sense), &sshdr);