dbg_check_tnc
int dbg_check_tnc(struct ubifs_info *c, int extra);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 0);
err = dbg_check_tnc(c, 1);