TTY: add tty_port_tty_hangup helper

It allows for cleaning up on a considerable amount of places. They did
port_get, hangup, kref_put. Now the only thing needed is to call
tty_port_tty_hangup which does exactly that. And they can also decide
whether to consider CLOCAL or completely ignore that.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index a7714b4..cba1d46 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -3124,18 +3124,13 @@
 static void hso_free_interface(struct usb_interface *interface)
 {
 	struct hso_serial *hso_dev;
-	struct tty_struct *tty;
 	int i;
 
 	for (i = 0; i < HSO_SERIAL_TTY_MINORS; i++) {
 		if (serial_table[i] &&
 		    (serial_table[i]->interface == interface)) {
 			hso_dev = dev2ser(serial_table[i]);
-			tty = tty_port_tty_get(&hso_dev->port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
+			tty_port_tty_hangup(&hso_dev->port, false);
 			mutex_lock(&hso_dev->parent->mutex);
 			hso_dev->parent->usb_gone = 1;
 			mutex_unlock(&hso_dev->parent->mutex);