dnet: replace obsolete *netif_rx_* functions with *napi_*

*netif_rx_* functions is obsolete and removed in newer kernels so
we need to use corresponding *napi_* functions instead.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>