nand_markbad_bbm
int nand_markbad_bbm(struct nand_chip *chip, loff_t ofs);
ret = nand_markbad_bbm(chip, ofs);
return nand_markbad_bbm(chip, nanddev_pos_to_offs(nand, pos));
res = nand_markbad_bbm(this, to);