int lfsr_init(struct fio_lfsr *fl, uint64_t size,
unsigned long seed, unsigned int spin);
int lfsr_reset(struct fio_lfsr *fl, unsigned long seed);
int lfsr_init(struct fio_lfsr *fl, uint64_t size,
unsigned long seed, unsigned int spin);
int lfsr_reset(struct fio_lfsr *fl, unsigned long seed);