litex_liteeth: Fix a double free in the remove function

'netdev' is a managed resource allocated in the probe using
'devm_alloc_etherdev()'.
It must not be freed explicitly in the remove function.

Fixes: ee7da21ac4c3 ("net: Add driver for LiteX's LiteETH network interface")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/litex/litex_liteeth.c b/drivers/net/ethernet/litex/litex_liteeth.c
index ab9fa15..fdd99f0 100644
--- a/drivers/net/ethernet/litex/litex_liteeth.c
+++ b/drivers/net/ethernet/litex/litex_liteeth.c
@@ -287,7 +287,6 @@ static int liteeth_remove(struct platform_device *pdev)
 	struct net_device *netdev = platform_get_drvdata(pdev);
 
 	unregister_netdev(netdev);
-	free_netdev(netdev);
 
 	return 0;
 }