korina: do schedule napi after testing for it

The called netif_rx_schedule() does all the work for us:
- it checks the return value of netif_rx_schedule_prep() and
- if everything is ok calls __netif_rx_schedule().
Before this change, the driver received absolutely nothing.

Signed-off-by: Phil Sutter <n0-1@freewrt.org>
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>