TTY: switch tty_insert_flip_string

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.

tty_insert_flip_string this time.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/iuu_phoenix.c b/drivers/usb/serial/iuu_phoenix.c
index 1e1fbed..dd0d910 100644
--- a/drivers/usb/serial/iuu_phoenix.c
+++ b/drivers/usb/serial/iuu_phoenix.c
@@ -596,7 +596,7 @@
 	if (data == NULL)
 		dev_dbg(&port->dev, "%s - data is NULL !!!\n", __func__);
 	if (tty && urb->actual_length && data) {
-		tty_insert_flip_string(tty, data, urb->actual_length);
+		tty_insert_flip_string(&port->port, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 	}
 	tty_kref_put(tty);