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

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

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/ibmvscsi/ibmvstgt.c b/drivers/scsi/ibmvscsi/ibmvstgt.c
index 82bcab6..d63f11e 100644
--- a/drivers/scsi/ibmvscsi/ibmvstgt.c
+++ b/drivers/scsi/ibmvscsi/ibmvstgt.c
@@ -292,7 +292,7 @@
 	dprintk("%p %p %x %u\n", iue, target, vio_iu(iue)->srp.cmd.cdb[0],
 		cmd->usg_sg);
 
-	if (sc->use_sg)
+	if (scsi_sg_count(sc))
 		err = srp_transfer_data(sc, &vio_iu(iue)->srp.cmd, ibmvstgt_rdma, 1, 1);
 
 	spin_lock_irqsave(&target->lock, flags);