net: am79c961a: Omit private ndo_get_stats function

am79c961_getstats() just returns dev->stats so we can leave it out
alltogether and let dev_get_stats() do the job.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>