io:core: In iio_map_array_register() cleanup in case of error

In function iio_map_array_register() properly rewind in case of error.

Signed-off-by: Lino Sanfilippo <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/inkern.c

···
 		i++;
 	}
 error_ret:
+	if (ret)
+		iio_map_array_unregister_locked(indio_dev);
 	mutex_unlock(&iio_map_list_lock);
 
 	return ret;