dbm_clearerr
#define dbm_clearerr(a) __db_ndbm_clearerr(a)
#define dbm_clearerr(__db) ((__db)->dbm_flags &= ~_DBM_IOERR)
#define dbm_clearerr kdb2_dbm_clearerr
#undef dbm_clearerr
dbm_clearerr(DBM *db)