TTY: serial_core, remove unused variable

drivers/tty/serial/serial_core.c:1980:2: warning: Value stored to 'tty' is never read
        tty = port->tty;
        ^     ~~~~~~~~~

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/serial_core.c

@@ -1972,13 +1972,9 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 	struct tty_port *port = &state->port;
 	struct device *tty_dev;
 	struct uart_match match = {uport, drv};
-	struct tty_struct *tty;
 
 	mutex_lock(&port->mutex);
 
-	/* Must be inside the mutex lock until we convert to tty_port */
-	tty = port->tty;
-
 	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
 	if (device_may_wakeup(tty_dev)) {
 		if (!enable_irq_wake(uport->irq))