tcm_fc: Remove use of transport_do_task_sg_chain()

With the modern target core, se_cmd->t_data_sg already points to a
sglist that covers the whole command.  So task_sg chaining is needless
overhead and obfuscation -- instead of splicing the split up task
sglists back into one list, we can just use the original list directly.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kiran Patil <Kiran.patil@intel.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index a375f25..f03fb97 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -215,20 +215,10 @@
 		 */
 		if ((ep->xid <= lport->lro_xid) &&
 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
-			if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
-				/*
-				 * cmd may have been broken up into multiple
-				 * tasks. Link their sgs together so we can
-				 * operate on them all at once.
-				 */
-				transport_do_task_sg_chain(se_cmd);
-				cmd->sg = se_cmd->t_tasks_sg_chained;
-				cmd->sg_cnt =
-					se_cmd->t_tasks_sg_chained_no;
-			}
-			if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
-							    cmd->sg,
-							    cmd->sg_cnt))
+			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) &&
+			    lport->tt.ddp_target(lport, ep->xid,
+						 se_cmd->t_data_sg,
+						 se_cmd->t_data_nents))
 				cmd->was_ddp_setup = 1;
 		}
 	}