tty: move the termios object into the tty

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 36a2a0b..bb2e37f 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -826,7 +826,7 @@
 						struct ktermios *termios_old)
 {
 	struct acm *acm = tty->driver_data;
-	struct ktermios *termios = tty->termios;
+	struct ktermios *termios = &tty->termios;
 	struct usb_cdc_line_coding newline;
 	int newctrl = acm->ctrlout;