[SCSI] scsi: sd, sr, st, and scsi_lib all fail to copy cmd_len to new cmd

This fixes an issue in scsi command initialization from a request
where sd, sr, st, and scsi_lib all fail to copy the request's
cmd_len to the scsi command's cmd_len field.

Signed-off-by: Timothy Thelin <timothy.thelin@wdc.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index ce63fc8..561901b 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -326,6 +326,7 @@
 			return 0;
 
 		memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
+		SCpnt->cmd_len = rq->cmd_len;
 		if (!rq->data_len)
 			SCpnt->sc_data_direction = DMA_NONE;
 		else if (rq_data_dir(rq) == WRITE)