net: ethernet: davinci_cpdma: decrease the desc count when cleaning up the remaining packets

chan->count is used by rx channel. If the desc count is not updated by
the clean up loop in cpdma_chan_stop, the value written to the rxfree
register in cpdma_chan_start will be incorrect.
Signed-off-by: NTao Hou <hotforest@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/davinci_cpdma.c

@@ -863,6 +863,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
 
 		next_dma = desc_read(desc, hw_next);
 		chan->head = desc_from_phys(pool, next_dma);
+		chan->count--;
 		chan->stats.teardown_dequeue++;
 
 		/* issue callback without locks held */