[TCP]: Introduce tcp_wnd_end() to reduce line lengths

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 76286e8..6a732d49 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -785,6 +785,12 @@
 	return 3;
 }
 
+/* Returns end sequence number of the receiver's advertised window */
+static inline u32 tcp_wnd_end(const struct tcp_sock *tp)
+{
+	return tp->snd_una + tp->snd_wnd;
+}
+
 /* RFC2861 Check whether we are limited by application or congestion window
  * This is the inverse of cwnd check in tcp_tso_should_defer
  */