e1000: ensure to free old tx/rx rings in set_ringparam()

In 'e1000_set_ringparam()', the tx_ring and rx_ring are updated with new value
and the old tx/rx rings are freed only when the device is up. There are resource
leaks on old tx/rx rings when the device is not up. This bug is reported by COD,
a tool for testing kernel module binaries I am building.

This patch fixes the bug by always calling 'kfree()' on old tx/rx rings in
'e1000_set_ringparam()'.
Signed-off-by: Bo Chen <chenbo@pdx.edu>
Reviewed-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000/e1000_ethtool.c

@@ -624,14 +624,14 @@ static int e1000_set_ringparam(struct net_device *netdev,
 		adapter->tx_ring = tx_old;
 		e1000_free_all_rx_resources(adapter);
 		e1000_free_all_tx_resources(adapter);
-		kfree(tx_old);
-		kfree(rx_old);
 		adapter->rx_ring = rxdr;
 		adapter->tx_ring = txdr;
 		err = e1000_up(adapter);
 		if (err)
 			goto err_setup;
 	}
+	kfree(tx_old);
+	kfree(rx_old);
 
 	clear_bit(__E1000_RESETTING, &adapter->flags);
 	return 0;