netronome: don't access real_num_rx_queues directly

The netdev->real_num_rx_queues setting is only available if CONFIG_SYSFS
is enabled, so we now get a build failure when that is turned off:

netronome/nfp/nfp_net_common.c: In function 'nfp_net_ring_swap_enable':
netronome/nfp/nfp_net_common.c:2489:18: error: 'struct net_device' has no member named 'real_num_rx_queues'; did you mean 'real_num_tx_queues'?

As far as I can tell, the check here is only used as an optimization that
we can skip in order to fix the compilation. If sysfs is disabled,
the following netif_set_real_num_rx_queues() has no effect.

Fixes: 164d1e9e5d52 ("nfp: add support for ethtool .set_channels")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -2486,15 +2486,13 @@ nfp_net_ring_swap_enable(struct nfp_net *nn, unsigned int *num_vecs,
 	for (r = 0; r <	nn->max_r_vecs; r++)
 		nfp_net_vector_assign_rings(nn, &nn->r_vecs[r], r);
 
-	if (nn->netdev->real_num_rx_queues != nn->num_rx_rings) {
-		if (!netif_is_rxfh_configured(nn->netdev))
-			nfp_net_rss_init_itbl(nn);
+	if (!netif_is_rxfh_configured(nn->netdev))
+		nfp_net_rss_init_itbl(nn);
 
-		err = netif_set_real_num_rx_queues(nn->netdev,
-						   nn->num_rx_rings);
-		if (err)
-			return err;
-	}
+	err = netif_set_real_num_rx_queues(nn->netdev,
+					   nn->num_rx_rings);
+	if (err)
+		return err;
 
 	if (nn->netdev->real_num_tx_queues != nn->num_stack_tx_rings) {
 		err = netif_set_real_num_tx_queues(nn->netdev,