et131x: check return value of dma_alloc_coherent

For error handling, dma_alloc_coherent's return value
needs to be checked, not argument.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/agere/et131x.c

@@ -2380,7 +2380,7 @@ static int et131x_tx_dma_memory_alloc(struct et131x_adapter *adapter)
 						    sizeof(u32),
 						    &tx_ring->tx_status_pa,
 						    GFP_KERNEL);
-	if (!tx_ring->tx_status_pa) {
+	if (!tx_ring->tx_status) {
 		dev_err(&adapter->pdev->dev,
 			"Cannot alloc memory for Tx status block\n");
 		return -ENOMEM;