Bluetooth: Clear ack_timer when sending ack

ack_timer should be cleared when sending ACK to avoid acking I-frames
twice.

This commit introduces helper function (only send ack, not clearing
timer) which is used by l2cap_send_ack and l2cap_ack_timeout. This is
to avoid clearing ack timer in timer function.
Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/l2cap_core.c

@@ -1478,7 +1478,7 @@ static int l2cap_retransmit_frames(struct l2cap_chan *chan)
 	return ret;
 }
 
-static void l2cap_send_ack(struct l2cap_chan *chan)
+static void __l2cap_send_ack(struct l2cap_chan *chan)
 {
 	u32 control = 0;
 
@@ -1498,6 +1498,12 @@ static void l2cap_send_ack(struct l2cap_chan *chan)
 	l2cap_send_sframe(chan, control);
 }
 
+static void l2cap_send_ack(struct l2cap_chan *chan)
+{
+	__clear_ack_timer(chan);
+	__l2cap_send_ack(chan);
+}
+
 static void l2cap_send_srejtail(struct l2cap_chan *chan)
 {
 	struct srej_list *tail;
@@ -1988,7 +1994,7 @@ static void l2cap_ack_timeout(struct work_struct *work)
 	BT_DBG("chan %p", chan);
 
 	lock_sock(chan->sk);
-	l2cap_send_ack(chan);
+	__l2cap_send_ack(chan);
 	release_sock(chan->sk);
 }