wireguard: device: remove generic .ndo_get_stats64

Commit 3e2f544 ("net: get stats64 if device if driver is
configured") moved the callback to dev_get_tstats64() to net core, so,
unless the driver is doing some custom stats collection, it does not
need to set .ndo_get_stats64.

Since this driver is now relying in NETDEV_PCPU_STAT_TSTATS, then, it
doesn't need to set the dev_get_tstats64() generic .ndo_get_stats64
function pointer.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/wireguard/device.c

@@ -237,7 +237,6 @@ static const struct net_device_ops netdev_ops = {
 	.ndo_open		= wg_open,
 	.ndo_stop		= wg_stop,
 	.ndo_start_xmit		= wg_xmit,
-	.ndo_get_stats64	= dev_get_tstats64
 };
 
 static void wg_destruct(struct net_device *dev)