[SCSI] iscsi_iser: convert to use the data buffer accessors

iscsi_iser: convert to use the data buffer accessors

- remove the unnecessary map_single path.

- convert to use the new accessors for the sg lists and the
parameters.

TODO: use scsi_for_each_sg().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 1bf173d..effdee2 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -210,10 +210,10 @@
 	int error = 0;
 
 	if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) {
-		BUG_ON(ctask->sc->request_bufflen == 0);
+		BUG_ON(scsi_bufflen(ctask->sc) == 0);
 
 		debug_scsi("cmd [itt %x total %d imm %d unsol_data %d\n",
-			   ctask->itt, ctask->sc->request_bufflen,
+			   ctask->itt, scsi_bufflen(ctask->sc),
 			   ctask->imm_count, ctask->unsol_count);
 	}