TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index cbec3b6..b6e44ad 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -541,23 +541,21 @@
 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
 {
 	struct rfcomm_dev *dev = dlc->owner;
-	struct tty_struct *tty;
 
 	if (!dev) {
 		kfree_skb(skb);
 		return;
 	}
 
-	tty = dev->port.tty;
-	if (!tty || !skb_queue_empty(&dev->pending)) {
+	if (!skb_queue_empty(&dev->pending)) {
 		skb_queue_tail(&dev->pending, skb);
 		return;
 	}
 
-	BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);
+	BT_DBG("dlc %p len %d", dlc, skb->len);
 
 	tty_insert_flip_string(&dev->port, skb->data, skb->len);
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(&dev->port);
 
 	kfree_skb(skb);
 }
@@ -621,14 +619,10 @@
 /* ---- TTY functions ---- */
 static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
 {
-	struct tty_struct *tty = dev->port.tty;
 	struct sk_buff *skb;
 	int inserted = 0;
 
-	if (!tty)
-		return;
-
-	BT_DBG("dev %p tty %p", dev, tty);
+	BT_DBG("dev %p", dev);
 
 	rfcomm_dlc_lock(dev->dlc);
 
@@ -641,7 +635,7 @@
 	rfcomm_dlc_unlock(dev->dlc);
 
 	if (inserted > 0)
-		tty_flip_buffer_push(tty);
+		tty_flip_buffer_push(&dev->port);
 }
 
 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)