[PATCH v2 1/6] dma/ioat: fix device stop if no copies done

[Walsh, Conor]

> The HW DMA devices supported by IOAT driver do not transition to
> the "active" state until the first operation is started by the HW.
> Therefore, if the user calls "rte_dma_stop()" on a device without
> triggering any operations, the sequence of commands to be sent to
> the HW is different, as is the final device state.
> 
> Update the IOAT driver "stop" function to take account of this
> difference.
> 
> Fixes: 583f046dd404 ("dma/ioat: add start and stop")
> Cc: conor.walsh at intel.com
> Cc: stable at dpdk.org
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>

Reviewed-by: Conor Walsh <conor.walsh at intel.com>