leds: ledtrig-tty: Free allocated ttyname buffer on deactivate

The ttyname buffer for the ledtrig_tty_data struct is allocated in the
sysfs ttyname_store() function. This buffer must be released on trigger
deactivation. This was missing and is thus a memory leak.

While we are at it, the TTY handler in the ledtrig_tty_data struct should
also be returned in case of the trigger deactivation call.

Cc: stable@vger.kernel.org
Fixes: fd4a641 ("leds: trigger: implement a tty trigger")
Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231127081621.774866-1-fe@dev.tdt.de
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/leds/trigger/ledtrig-tty.c

@@ -168,6 +168,10 @@ static void ledtrig_tty_deactivate(struct led_classdev *led_cdev)
 
 	cancel_delayed_work_sync(&trigger_data->dwork);
 
+	kfree(trigger_data->ttyname);
+	tty_kref_put(trigger_data->tty);
+	trigger_data->tty = NULL;
+
 	kfree(trigger_data);
 }