tty: fix missing assignment

We're trying to save the termios state and we need to allocate a buffer
to do it.  Smatch complains that the buffer is leaked at the end of the
function.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -1450,6 +1450,7 @@ void tty_free_termios(struct tty_struct *tty)
 			pr_warn("tty: no memory to save termios state.\n");
 			return;
 		}
+		tty->driver->termios[idx] = tp;
 	}
 	*tp = tty->termios;
 }