btrfs: Remove unused sectorsize variable from struct map_lookup

This variable was added in 1abe9b8a ("Btrfs: add initial tracepointi
support for btrfs"), yet it never really got used, only assigned to. So
let's remove it.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -4791,7 +4791,6 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 						   j * stripe_size;
 		}
 	}
-	map->sector_size = info->sectorsize;
 	map->stripe_len = BTRFS_STRIPE_LEN;
 	map->io_align = BTRFS_STRIPE_LEN;
 	map->io_width = BTRFS_STRIPE_LEN;
@@ -6443,7 +6442,6 @@ static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
 	map->num_stripes = num_stripes;
 	map->io_width = btrfs_chunk_io_width(leaf, chunk);
 	map->io_align = btrfs_chunk_io_align(leaf, chunk);
-	map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
 	map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
 	map->type = btrfs_chunk_type(leaf, chunk);
 	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);

fs/btrfs/volumes.h

@@ -353,7 +353,6 @@ struct map_lookup {
 	int io_align;
 	int io_width;
 	u64 stripe_len;
-	int sector_size;
 	int num_stripes;
 	int sub_stripes;
 	struct btrfs_bio_stripe stripes[];