tty: serial - fix tty back references in termios

One or two drivers go poking back into the tty from the termios setting
routine in unsafe ways. We don't need to pass the tty down because the
[ab]users are just using it to get at things they can get at anyway.

This leaves low_latency setting to sort out along with set_ldisc use.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/serial/21285.c b/drivers/serial/21285.c
index 8681f13..d89aa38 100644
--- a/drivers/serial/21285.c
+++ b/drivers/serial/21285.c
@@ -216,7 +216,7 @@
 			struct ktermios *old)
 {
 	unsigned long flags;
-	unsigned int baud, quot, h_lcr;
+	unsigned int baud, quot, h_lcr, b;
 
 	/*
 	 * We don't support modem control lines.
@@ -234,12 +234,8 @@
 	 */
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
 	quot = uart_get_divisor(port, baud);
-
-	if (port->state && port->state->port.tty) {
-		struct tty_struct *tty = port->state->port.tty;
-		unsigned int b = port->uartclk / (16 * quot);
-		tty_encode_baud_rate(tty, b, b);
-	}
+	b = port->uartclk / (16 * quot);
+	tty_termios_encode_baud_rate(termios, b, b);
 
 	switch (termios->c_cflag & CSIZE) {
 	case CS5: