tty: Move the handling of the tty release logic

Now that we don't have tty->termios tied to drivers->tty we can untangle
the logic here. In addition we can push the removal logic out of the
destructor path.

At that point we can think about sorting out tty_port and console and all
the other ugly hangovers.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 04419c1..80e72dc 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -45,14 +45,9 @@
  *
  * void (*shutdown)(struct tty_struct * tty);
  *
- * 	This routine is called synchronously when a particular tty device
- *	is closed for the last time freeing up the resources.
- *	Note that tty_shutdown() is not called if ops->shutdown is defined.
- *	This means one is responsible to take care of calling ops->remove (e.g.
- *	via tty_driver_remove_tty) and releasing tty->termios.
- *	Note that this hook may be called from *all* the contexts where one
- *	uses tty refcounting (e.g. tty_port_tty_get).
- *
+ * 	This routine is called under the tty lock when a particular tty device
+ *	is closed for the last time. It executes before the tty resources
+ *	are freed so may execute while another function holds a tty kref.
  *
  * void (*cleanup)(struct tty_struct * tty);
  *