tcp: tcp_sendmsg() wrong access to sk_route_caps

Now sk_route_caps is u64, its dangerous to use an integer to store
result of an AND operator. It wont work if NETIF_F_SG is moved on the
upper part of u64.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp.c

@@ -891,7 +891,7 @@ EXPORT_SYMBOL(tcp_sendpage);
 #define TCP_PAGE(sk)	(sk->sk_sndmsg_page)
 #define TCP_OFF(sk)	(sk->sk_sndmsg_off)
 
-static inline int select_size(const struct sock *sk, int sg)
+static inline int select_size(const struct sock *sk, bool sg)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	int tmp = tp->mss_cache;
@@ -917,9 +917,9 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	struct iovec *iov;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
-	int iovlen, flags;
+	int iovlen, flags, err, copied;
 	int mss_now, size_goal;
-	int sg, err, copied;
+	bool sg;
 	long timeo;
 
 	lock_sock(sk);
@@ -946,7 +946,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 		goto out_err;
 
-	sg = sk->sk_route_caps & NETIF_F_SG;
+	sg = !!(sk->sk_route_caps & NETIF_F_SG);
 
 	while (--iovlen >= 0) {
 		size_t seglen = iov->iov_len;