gpiolib: cdev: gpio_desc_to_lineinfo() should set info offset

Set the value of the line info offset in gpio_desc_to_lineinfo(), rather
than relying on it being passed in the info.  This makes the function
behave as you would expect from the name - it generates the line info
corresponding to a given GPIO desc.
Signed-off-by: NKent Gibson <warthog618@gmail.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpiolib-cdev.c

@@ -752,6 +752,8 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 	bool ok_for_pinctrl;
 	unsigned long flags;
 
+	info->line_offset = gpio_chip_hwgpio(desc);
+
 	/*
 	 * This function takes a mutex so we must check this before taking
 	 * the spinlock.
@@ -933,7 +935,6 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
 		return NOTIFY_DONE;
 
 	memset(&chg, 0, sizeof(chg));
-	chg.info.line_offset = gpio_chip_hwgpio(desc);
 	chg.event_type = action;
 	chg.timestamp = ktime_get_ns();
 	gpio_desc_to_lineinfo(desc, &chg.info);