net-timestamp: optimize sock_tx_timestamp default path

Few packets have timestamping enabled. Exit sock_tx_timestamp quickly
in this common case.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/socket.c b/net/socket.c
index 2e2586e..d40f522 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -610,7 +610,7 @@
 }
 EXPORT_SYMBOL(sock_release);
 
-void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags)
+void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags)
 {
 	u8 flags = *tx_flags;
 
@@ -626,12 +626,9 @@
 	if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK)
 		flags |= SKBTX_ACK_TSTAMP;
 
-	if (sock_flag(sk, SOCK_WIFI_STATUS))
-		flags |= SKBTX_WIFI_STATUS;
-
 	*tx_flags = flags;
 }
-EXPORT_SYMBOL(sock_tx_timestamp);
+EXPORT_SYMBOL(__sock_tx_timestamp);
 
 static inline int __sock_sendmsg_nosec(struct kiocb *iocb, struct socket *sock,
 				       struct msghdr *msg, size_t size)