[PATCH v2 3/6] dma/ioat: fix incorrect error reporting on restart

[Walsh, Conor]

> When the DMA device was stopped and restarted by the driver, the control
> register specifying the behaviour on error was not getting correctly
> reset. This caused unit tests to fail as explicitly introduced errors
> were got getting reported back.
> 
> Fix by moving the setting of the register to the start function from the
> probe function.
> 
> 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>