__get_key_name
name = __get_key_name(class->key, str);
name = __get_key_name(lock->key->subkeys, str);
extern const char *__get_key_name(const struct lockdep_subclass_key *key,
key_name = __get_key_name(ckey, str);
name = __get_key_name(class->key, str);