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/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index 203358d..498b5f0 100644
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -256,7 +256,7 @@
 
 	if (tty && actual_length) {
 		usb_serial_debug_data(&port->dev, __func__, actual_length, data);
-		tty_insert_flip_string(tty, data, actual_length);
+		tty_insert_flip_string(&port->port, data, actual_length);
 		tty_flip_buffer_push(tty);
 	}
 	tty_kref_put(tty);