* for-5.15/drivers:
nbd: remove nbd->destroy_complete
nbd: only return usable devices from nbd_find_unused
nbd: set nbd->index before releasing nbd_index_mutex
nbd: prevent IDR lookups from finding partially initialized devices
nbd: reset NBD to NULL when restarting in nbd_genl_connect
nbd: add missing locking to the nbd_dev_add error path