driver core: make subsys_dev_iter_next() static

The function subsys_dev_iter_next() is only used in drivers/base/bus.c
so make it static to that file and remove the global export.
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230109175810.2965448-4-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/bus.c

@@ -946,7 +946,7 @@ static void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *
  * free to do whatever it wants to do with the device including
  * calling back into subsys code.
  */
-struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
+static struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
 {
 	struct klist_node *knode;
 	struct device *dev;
@@ -960,7 +960,6 @@ struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
 			return dev;
 	}
 }
-EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
 
 /**
  * subsys_dev_iter_exit - finish iteration

include/linux/device/bus.h

@@ -154,7 +154,6 @@ struct subsys_dev_iter {
 	struct klist_iter		ki;
 	const struct device_type	*type;
 };
-struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
 
 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,