tipc: Remove unused macro TIPC_NACK_INTV

There is no caller in tree any more.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -216,11 +216,6 @@ enum {
 #define TIPC_BC_RETR_LIM  (jiffies + msecs_to_jiffies(10))
 #define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
 
-/*
- * Interval between NACKs when packets arrive out of order
- */
-#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
-
 /* Link FSM states:
  */
 enum {