netdev: restore MTU change operation

alloc_etherdev() used to install a default implementation of this
operation, but it must now be explicitly installed in struct
net_device_ops.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/via-rhine.c b/drivers/net/via-rhine.c
index d3489a3..88c30a5 100644
--- a/drivers/net/via-rhine.c
+++ b/drivers/net/via-rhine.c
@@ -621,6 +621,7 @@
 	.ndo_start_xmit		 = rhine_start_tx,
 	.ndo_get_stats		 = rhine_get_stats,
 	.ndo_set_multicast_list	 = rhine_set_rx_mode,
+	.ndo_change_mtu		 = eth_change_mtu,
 	.ndo_validate_addr	 = eth_validate_addr,
 	.ndo_set_mac_address 	 = eth_mac_addr,
 	.ndo_do_ioctl		 = netdev_ioctl,