I/OAT: list usage cleanup

Trivial cleanup, list_del(); list_add_tail() is equivalent
to list_move_tail(). Semantic patch for coccinelle can be
found at www.cccmz.de/~snakebyte/list_move_tail.spatch

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/ioat_dma.c

@@ -1171,9 +1171,8 @@ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan)
 				 * up if the client is done with the descriptor
 				 */
 				if (async_tx_test_ack(&desc->async_tx)) {
-					list_del(&desc->node);
-					list_add_tail(&desc->node,
-						      &ioat_chan->free_desc);
+					list_move_tail(&desc->node,
+						       &ioat_chan->free_desc);
 				} else
 					desc->async_tx.cookie = 0;
 			} else {