gpio: fix spurious printk when freeing a gpio

When freeing a gpio that has not been exported, gpio_unexport() prints a
debug message when it should just fall through silently.

Example spurious message:

	gpio_unexport: gpio0 status -22
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>
Cc: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/gpiolib.c

@@ -893,10 +893,12 @@ EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low);
 void gpio_unexport(unsigned gpio)
 {
 	struct gpio_desc	*desc;
-	int			status = -EINVAL;
+	int			status = 0;
 
-	if (!gpio_is_valid(gpio))
+	if (!gpio_is_valid(gpio)) {
+		status = -EINVAL;
 		goto done;
+	}
 
 	mutex_lock(&sysfs_lock);
 
@@ -911,7 +913,6 @@ void gpio_unexport(unsigned gpio)
 			clear_bit(FLAG_EXPORT, &desc->flags);
 			put_device(dev);
 			device_unregister(dev);
-			status = 0;
 		} else
 			status = -ENODEV;
 	}