btrfs: remove btrfs_bio_for_each_sector

btrfs_bio_for_each_sector is unused now, so remove it.
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/bio.h

@@ -94,22 +94,6 @@ static inline void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
 	bbio->end_io(bbio);
 }
 
-/*
- * Iterate through a btrfs_bio (@bbio) on a per-sector basis.
- *
- * bvl        - struct bio_vec
- * bbio       - struct btrfs_bio
- * iters      - struct bvec_iter
- * bio_offset - unsigned int
- */
-#define btrfs_bio_for_each_sector(fs_info, bvl, bbio, iter, bio_offset)	\
-	for ((iter) = (bbio)->iter, (bio_offset) = 0;			\
-	     (iter).bi_size &&					\
-	     (((bvl) = bio_iter_iovec((&(bbio)->bio), (iter))), 1);	\
-	     (bio_offset) += fs_info->sectorsize,			\
-	     bio_advance_iter_single(&(bbio)->bio, &(iter),		\
-	     (fs_info)->sectorsize))
-
 void btrfs_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 		      int mirror_num);
 int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,