net: remove netif_set_real_num_rx_queues() helper for when SYSFS=n

Since commit a953be5 ("net-sysfs: add support for device-specific
rx queue sysfs attributes"), so for at least a decade now it is safe
to call net_rx_queue_update_kobjects() when SYSFS=n. That function
does its own ifdef-inery and will return 0. Remove the unnecessary
stub for netif_set_real_num_rx_queues().

Acked-by: Stanislav Fomichev <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

include/linux/netdevice.h

@@ -4062,17 +4062,7 @@ static inline bool netif_is_multiqueue(const struct net_device *dev)
 }
 
 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq);
-
-#ifdef CONFIG_SYSFS
 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq);
-#else
-static inline int netif_set_real_num_rx_queues(struct net_device *dev,
-						unsigned int rxqs)
-{
-	dev->real_num_rx_queues = rxqs;
-	return 0;
-}
-#endif
 int netif_set_real_num_queues(struct net_device *dev,
 			      unsigned int txq, unsigned int rxq);
 

net/core/dev.c

@@ -3160,7 +3160,6 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
 }
 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
 
-#ifdef CONFIG_SYSFS
 /**
  *	netif_set_real_num_rx_queues - set actual number of RX queues used
  *	@dev: Network device
@@ -3191,7 +3190,6 @@ int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
 	return 0;
 }
 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
-#endif
 
 /**
  *	netif_set_real_num_queues - set actual number of RX and TX queues used