net: dsa: remove dsa_uses_tagged_protocol

Since dev->dsa_ptr is a pointer to a dsa_switch_tree, there is no need
to have another inline helper just to check rcv.

Remove dsa_uses_tagged_protocol and check dsa_ptr && dsa_ptr->rcv
together at the same time.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -468,16 +468,10 @@ struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev);
 struct net_device *dsa_dev_to_net_device(struct device *dev);
 
 /* Keep inline for faster access in hot path */
-static inline bool dsa_uses_tagged_protocol(struct dsa_switch_tree *dst)
-{
-	return dst->rcv != NULL;
-}
-
 static inline bool netdev_uses_dsa(struct net_device *dev)
 {
 #if IS_ENABLED(CONFIG_NET_DSA)
-	if (dev->dsa_ptr != NULL)
-		return dsa_uses_tagged_protocol(dev->dsa_ptr);
+	return dev->dsa_ptr && dev->dsa_ptr->rcv;
 #endif
 	return false;
 }