Input: ps2-gpio - flush TX work when closing port

To ensure that TX work is not running after serio port has been torn down,
let's flush it when closing the port.

Reported-by: Sven Van Asbroeck <thesven73@gmail.com>
Acked-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/serio/ps2-gpio.c

@@ -76,6 +76,7 @@ static void ps2_gpio_close(struct serio *serio)
 {
 	struct ps2_gpio_data *drvdata = serio->port_data;
 
+	flush_delayed_work(&drvdata->tx_work);
 	disable_irq(drvdata->irq);
 }