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/ipv4/udp.c b/net/ipv4/udp.c
index 8f4158d..80e3812 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -840,7 +840,8 @@
 	switch (cmd) {
 	case SIOCOUTQ:
 	{
-		int amount = atomic_read(&sk->sk_wmem_alloc);
+		int amount = sk_wmem_alloc_get(sk);
+
 		return put_user(amount, (int __user *)arg);
 	}
 
@@ -1721,8 +1722,8 @@
 	seq_printf(f, "%4d: %08X:%04X %08X:%04X"
 		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
 		bucket, src, srcp, dest, destp, sp->sk_state,
-		atomic_read(&sp->sk_wmem_alloc),
-		atomic_read(&sp->sk_rmem_alloc),
+		sk_wmem_alloc_get(sp),
+		sk_rmem_alloc_get(sp),
 		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
 		atomic_read(&sp->sk_refcnt), sp,
 		atomic_read(&sp->sk_drops), len);