[SCSI] iscsi: Some fixes in preparation for bidirectional support - total_length

- Remove shadow of request length from struct iscsi_cmd_task.
- change all users to use scsi_cmnd->request_bufflen directly

(With bidi we will use scsi-ml API to retrieve in/out length)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index eb51136..0a9c64e 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -147,19 +147,19 @@
 		ctask->unsol_datasn = 0;
 
 		if (session->imm_data_en) {
-			if (ctask->total_length >= session->first_burst)
+			if (sc->request_bufflen >= session->first_burst)
 				ctask->imm_count = min(session->first_burst,
 							conn->max_xmit_dlength);
 			else
-				ctask->imm_count = min(ctask->total_length,
+				ctask->imm_count = min(sc->request_bufflen,
 							conn->max_xmit_dlength);
 			hton24(ctask->hdr->dlength, ctask->imm_count);
 		} else
 			zero_data(ctask->hdr->dlength);
 
 		if (!session->initial_r2t_en) {
-			ctask->unsol_count = min(session->first_burst,
-				ctask->total_length) - ctask->imm_count;
+			ctask->unsol_count = min((session->first_burst),
+				(sc->request_bufflen)) - ctask->imm_count;
 			ctask->unsol_offset = ctask->imm_count;
 		}
 
@@ -815,7 +815,6 @@
 	ctask->conn = conn;
 	ctask->sc = sc;
 	INIT_LIST_HEAD(&ctask->running);
-	ctask->total_length = sc->request_bufflen;
 	iscsi_prep_scsi_cmd_pdu(ctask);
 
 	session->tt->init_cmd_task(ctask);