KS8695: fix ks8695_rx() unreasonable action.

ks8695_rx() will call refill_buffers() for every incoming packet.
Its not necessary. We just need do it after finishing receiving thing.
And the 'RX dma engine' is in the same situation.
This blocks our user space application. The following patch may fix it.

Signed-off-by: zeal <zealcook@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>