net: ipv4: Change variable type to bool

The variable fully_acked is only assigned the values true and false.
Change its type to bool.

The simplified semantic patch that find this problem is as
follows (http://coccinelle.lip6.fr/):

@exists@
type T;
identifier b;
@@
- T
+ bool
  b = ...;
  ... when any
  b = \(true\|false\)
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

@@ -3012,7 +3012,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct sk_buff *skb;
 	u32 now = tcp_time_stamp;
-	int fully_acked = true;
+	bool fully_acked = true;
 	int flag = 0;
 	u32 pkts_acked = 0;
 	u32 reord = tp->packets_out;