gpiolib: Deduplicate cleanup for-loop in gpiochip_add_data_with_key()

There is no need to repeat for-loop twice in the error path in
gpiochip_add_data_with_key(). Deduplicate it. While at it,
rename loop variable to be more specific and avoid ambguity.

It also properly unwinds the SRCU, i.e. in reversed order of allocating.

Signed-off-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpiolib.c

···
 			       struct lock_class_key *request_key)
 {
 	struct gpio_device *gdev;
-	unsigned int i, j;
+	unsigned int desc_index;
 	int base = 0;
 	int ret = 0;
 
···
 		}
 	}
 
-	for (i = 0; i < gc->ngpio; i++)
-		gdev->descs[i].gdev = gdev;
+	for (desc_index = 0; desc_index < gc->ngpio; desc_index++)
+		gdev->descs[desc_index].gdev = gdev;
 
 	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
 	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
···
 	if (ret)
 		goto err_cleanup_gdev_srcu;
 
-	for (i = 0; i < gc->ngpio; i++) {
-		struct gpio_desc *desc = &gdev->descs[i];
+	for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
+		struct gpio_desc *desc = &gdev->descs[desc_index];
 
 		ret = init_srcu_struct(&desc->srcu);
-		if (ret) {
-			for (j = 0; j < i; j++)
-				cleanup_srcu_struct(&gdev->descs[j].srcu);
-			goto err_free_gpiochip_mask;
-		}
+		if (ret)
+			goto err_cleanup_desc_srcu;
 
-		if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
+		if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
 			assign_bit(FLAG_IS_OUT,
-				   &desc->flags, !gc->get_direction(gc, i));
+				   &desc->flags, !gc->get_direction(gc, desc_index));
 		} else {
 			assign_bit(FLAG_IS_OUT,
 				   &desc->flags, !gc->direction_input);
···
 err_remove_of_chip:
 	of_gpiochip_remove(gc);
 err_cleanup_desc_srcu:
-	for (i = 0; i < gdev->ngpio; i++)
-		cleanup_srcu_struct(&gdev->descs[i].srcu);
-err_free_gpiochip_mask:
+	while (desc_index--)
+		cleanup_srcu_struct(&gdev->descs[desc_index].srcu);
 	gpiochip_free_valid_mask(gc);
 err_cleanup_gdev_srcu:
 	cleanup_srcu_struct(&gdev->srcu);