net: correct off-by-one write allocations reports

commit 2b85a34e91
(net: No more expensive sock_hold()/sock_put() on each tx)
changed initial sk_wmem_alloc value.

We need to take into account this offset when reporting
sk_wmem_alloc to user, in PROC_FS files or various
ioctls (SIOCOUTQ/TIOCOUTQ)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/appletalk/atalk_proc.c

@@ -204,8 +204,8 @@ static int atalk_seq_socket_show(struct seq_file *seq, void *v)
 			"%02X %d\n",
 		   s->sk_type, ntohs(at->src_net), at->src_node, at->src_port,
 		   ntohs(at->dest_net), at->dest_node, at->dest_port,
-		   atomic_read(&s->sk_wmem_alloc),
-		   atomic_read(&s->sk_rmem_alloc),
+		   sk_wmem_alloc_get(s),
+		   sk_rmem_alloc_get(s),
 		   s->sk_state, SOCK_INODE(s->sk_socket)->i_uid);
 out:
 	return 0;

net/appletalk/ddp.c

@@ -1748,8 +1748,7 @@ static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 	switch (cmd) {
 		/* Protocol layer */
 		case TIOCOUTQ: {
-			long amount = sk->sk_sndbuf -
-				      atomic_read(&sk->sk_wmem_alloc);
+			long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
 
 			if (amount < 0)
 				amount = 0;