staging:iio:core simplify and fix a bug in iio_device_(un)register_event_set.

The unwinding index was j, not i and it is much simpler to do these as a single
loop unwinding those elements necessary in before jumping to the error handler.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/industrialio-core.c

@@ -1061,7 +1061,7 @@ static int iio_device_register_eventset(struct iio_dev *dev_info)
 		if (ret) {
 			dev_err(&dev_info->dev,
 				"Could not get chrdev interface\n");
-			goto error_free_setup_ev_ints;
+			goto error_free_setup_event_lines;
 		}
 
 		dev_set_drvdata(&dev_info->event_interfaces[i].dev,
@@ -1077,31 +1077,33 @@ static int iio_device_register_eventset(struct iio_dev *dev_info)
 		if (ret) {
 			dev_err(&dev_info->dev,
 				"Failed to register sysfs for event attrs");
-			goto error_remove_sysfs_interfaces;
-		}
+			iio_free_ev_int(&dev_info->event_interfaces[i]);
+			goto error_free_setup_event_lines;
 		}
-
-	for (i = 0; i < dev_info->info->num_interrupt_lines; i++) {
 		ret = __iio_add_event_config_attrs(dev_info, i);
-		if (ret)
-			goto error_unregister_config_attrs;
+		if (ret) {
+			if (dev_info->info->event_attrs != NULL)
+				sysfs_remove_group(&dev_info
+						   ->event_interfaces[i]
+						   .dev.kobj,
+						   &dev_info->info
+						   ->event_attrs[i]);
+			iio_free_ev_int(&dev_info->event_interfaces[i]);
+			goto error_free_setup_event_lines;
+		}
 	}
 
 	return 0;
 
-error_unregister_config_attrs:
-	for (j = 0; j < i; j++)
-		__iio_remove_event_config_attrs(dev_info, i);
-	i = dev_info->info->num_interrupt_lines - 1;
-error_remove_sysfs_interfaces:
-	for (j = 0; j < i; j++)
+error_free_setup_event_lines:
+	for (j = 0; j < i; j++) {
+		__iio_remove_event_config_attrs(dev_info, j);
 		if (dev_info->info->event_attrs != NULL)
 			sysfs_remove_group(&dev_info
 					   ->event_interfaces[j].dev.kobj,
 					   &dev_info->info->event_attrs[j]);
-error_free_setup_ev_ints:
-	for (j = 0; j < i; j++)
 		iio_free_ev_int(&dev_info->event_interfaces[j]);
+	}
 	kfree(dev_info->event_interfaces);
 error_ret:
 
@@ -1120,10 +1122,8 @@ static void iio_device_unregister_eventset(struct iio_dev *dev_info)
 			sysfs_remove_group(&dev_info
 					   ->event_interfaces[i].dev.kobj,
 					   &dev_info->info->event_attrs[i]);
-	}
-
-	for (i = 0; i < dev_info->info->num_interrupt_lines; i++)
 		iio_free_ev_int(&dev_info->event_interfaces[i]);
+	}
 	kfree(dev_info->event_interfaces);
 }