net: Update generic_xdp_needed static key to modern api

No changes in refcount semantics -- key init is false; replace

static_key_slow_inc|dec   with   static_branch_inc|dec
static_key_false          with   static_branch_unlikely

Added a '_key' suffix to generic_xdp_needed, for better self
documentation.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -4154,7 +4154,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
 }
 EXPORT_SYMBOL_GPL(generic_xdp_tx);
 
-static struct static_key generic_xdp_needed __read_mostly;
+static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
 
 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
 {
@@ -4194,7 +4194,7 @@ static int netif_rx_internal(struct sk_buff *skb)
 
 	trace_netif_rx(skb);
 
-	if (static_key_false(&generic_xdp_needed)) {
+	if (static_branch_unlikely(&generic_xdp_needed_key)) {
 		int ret;
 
 		preempt_disable();
@@ -4726,9 +4726,9 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
 			bpf_prog_put(old);
 
 		if (old && !new) {
-			static_key_slow_dec(&generic_xdp_needed);
+			static_branch_dec(&generic_xdp_needed_key);
 		} else if (new && !old) {
-			static_key_slow_inc(&generic_xdp_needed);
+			static_branch_inc(&generic_xdp_needed_key);
 			dev_disable_lro(dev);
 			dev_disable_gro_hw(dev);
 		}
@@ -4756,7 +4756,7 @@ static int netif_receive_skb_internal(struct sk_buff *skb)
 	if (skb_defer_rx_timestamp(skb))
 		return NET_RX_SUCCESS;
 
-	if (static_key_false(&generic_xdp_needed)) {
+	if (static_branch_unlikely(&generic_xdp_needed_key)) {
 		int ret;
 
 		preempt_disable();