gpio: sim: fix the chip_name configfs item

The chip_name configs attribute always displays the device name of the
first GPIO bank because the logic of the relevant function is simply
wrong.

Fix it by correctly comparing the bank's swnode against the GPIO
device's children.

Fixes: cb8c474e ("gpio: sim: new testing module")
Cc: stable@vger.kernel.org
Reported-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Tested-by: Kent Gibson <warthog618@gmail.com>

drivers/gpio/gpio-sim.c

@@ -991,28 +991,22 @@ static struct configfs_attribute *gpio_sim_device_config_attrs[] = {
 };
 
 struct gpio_sim_chip_name_ctx {
-	struct gpio_sim_device *dev;
+	struct fwnode_handle *swnode;
 	char *page;
 };
 
 static int gpio_sim_emit_chip_name(struct device *dev, void *data)
 {
 	struct gpio_sim_chip_name_ctx *ctx = data;
-	struct fwnode_handle *swnode;
-	struct gpio_sim_bank *bank;
 
 	/* This would be the sysfs device exported in /sys/class/gpio. */
 	if (dev->class)
 		return 0;
 
-	swnode = dev_fwnode(dev);
+	if (device_match_fwnode(dev, ctx->swnode))
+		return sprintf(ctx->page, "%s\n", dev_name(dev));
 
-	list_for_each_entry(bank, &ctx->dev->bank_list, siblings) {
-		if (bank->swnode == swnode)
-			return sprintf(ctx->page, "%s\n", dev_name(dev));
-	}
-
-	return -ENODATA;
+	return 0;
 }
 
 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
@@ -1020,7 +1014,7 @@ static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
 {
 	struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
 	struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
-	struct gpio_sim_chip_name_ctx ctx = { dev, page };
+	struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page };
 	int ret;
 
 	mutex_lock(&dev->lock);