btrfs: move btrfs_ordered_sum_size into file-item.c

This is defined in ordered-data.h, but is only used in file-item.c.
Move this to file-item.c as it doesn't need to be global.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/file-item.c

@@ -129,6 +129,17 @@ static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
 	return ncsums * fs_info->sectorsize;
 }
 
+/*
+ * Calculate the total size needed to allocate for an ordered sum structure
+ * spanning @bytes in the file.
+ */
+static int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info, unsigned long bytes)
+{
+	int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
+
+	return sizeof(struct btrfs_ordered_sum) + num_sectors * fs_info->csum_size;
+}
+
 int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     u64 objectid, u64 pos, u64 num_bytes)

fs/btrfs/ordered-data.h

@@ -160,18 +160,6 @@ struct btrfs_ordered_extent {
 	struct block_device *bdev;
 };
 
-/*
- * calculates the total size you need to allocate for an ordered sum
- * structure spanning 'bytes' in the file
- */
-static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
-					 unsigned long bytes)
-{
-	int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
-
-	return sizeof(struct btrfs_ordered_sum) + num_sectors * fs_info->csum_size;
-}
-
 static inline void
 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 {