net: correct off-by-one write allocations reports

commit 2b85a34e911bf483c27cfdd124aeb1605145dc80
(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>
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 61b35b9..da0f64f 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1690,7 +1690,8 @@
 	switch (cmd) {
 	case TIOCOUTQ: {
 		long amount;
-		amount = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
+
+		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
 		if (amount < 0)
 			amount = 0;
 		res = put_user(amount, (int __user *)argp);
@@ -1780,8 +1781,8 @@
 		ax25_info.idletimer = ax25_display_timer(&ax25->idletimer) / (60 * HZ);
 		ax25_info.n2count   = ax25->n2count;
 		ax25_info.state     = ax25->state;
-		ax25_info.rcv_q     = atomic_read(&sk->sk_rmem_alloc);
-		ax25_info.snd_q     = atomic_read(&sk->sk_wmem_alloc);
+		ax25_info.rcv_q     = sk_wmem_alloc_get(sk);
+		ax25_info.snd_q     = sk_rmem_alloc_get(sk);
 		ax25_info.vs        = ax25->vs;
 		ax25_info.vr        = ax25->vr;
 		ax25_info.va        = ax25->va;
@@ -1921,8 +1922,8 @@
 
 	if (ax25->sk != NULL) {
 		seq_printf(seq, " %d %d %lu\n",
-			   atomic_read(&ax25->sk->sk_wmem_alloc),
-			   atomic_read(&ax25->sk->sk_rmem_alloc),
+			   sk_wmem_alloc_get(ax25->sk),
+			   sk_rmem_alloc_get(ax25->sk),
 			   sock_i_ino(ax25->sk));
 	} else {
 		seq_puts(seq, " * * *\n");