net: eth: altera: fix napi poll_list corruption

tse_poll() calls __napi_complete() with irq enabled.  This leads napi
poll_list corruption and may stop all napi drivers working.
Use napi_complete() instead of __napi_complete().

Signed-off-by: Atsushi Nemoto <nemoto@toshiba-tops.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>