459f79235d
This is a functionally equivalent replacement of the current reference counting of struct fw_card instances. It only converts it to common idioms as suggested by Kristian Høgsberg: - struct kref replaces atomic_t as the counter. - wait_for_completion is used to wait for all card users to complete. BTW, it may make sense to count card->flush_timer and card->work as card users too. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>