btrfs: move btrfs_next_old_item into ctree.c

This uses btrfs_header_nritems, which I will be moving out of ctree.h.
In order to avoid needing to include the relevant header in ctree.h,
simply move this helper function into ctree.c.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename parameters ]
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.c

@@ -4852,6 +4852,14 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 	return ret;
 }
 
+int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq)
+{
+	path->slots[0]++;
+	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
+		return btrfs_next_old_leaf(root, path, time_seq);
+	return 0;
+}
+
 /*
  * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
  * searching until it gets past min_objectid or finds an item of 'type'

fs/btrfs/ctree.h

@@ -2821,14 +2821,7 @@ int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
 		(path)->slots[0]++						\
 	)
 
-static inline int btrfs_next_old_item(struct btrfs_root *root,
-				      struct btrfs_path *p, u64 time_seq)
-{
-	++p->slots[0];
-	if (p->slots[0] >= btrfs_header_nritems(p->nodes[0]))
-		return btrfs_next_old_leaf(root, p, time_seq);
-	return 0;
-}
+int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
 
 /*
  * Search the tree again to find a leaf with greater keys.