dma: tegra20-apb-dma: remove unnecessary assignment

There is no need to assign 0 to residue, because dma_cookie_status() does this
for us.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/tegra20-apb-dma.c

@@ -767,7 +767,6 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 
 	ret = dma_cookie_status(dc, cookie, txstate);
 	if (ret == DMA_SUCCESS) {
-		dma_set_residue(txstate, 0);
 		spin_unlock_irqrestore(&tdc->lock, flags);
 		return ret;
 	}