btrfs: remove btrfs_read_fs_root, not used anymore

All helpers should either be using btrfs_get_fs_root() or
btrfs_read_tree_root().
Reviewed-by: Nikolay Borisov <nborisov@suse.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/disk-io.c

@@ -1437,17 +1437,6 @@ struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
 	goto out;
 }
 
-struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
-				      struct btrfs_key *location)
-{
-	struct btrfs_root *root;
-
-	root = btrfs_read_tree_root(tree_root, location);
-	if (IS_ERR(root))
-		return root;
-	return root;
-}
-
 int btrfs_init_fs_root(struct btrfs_root *root)
 {
 	int ret;
@@ -1568,7 +1557,7 @@ struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
 		return root;
 	}
 
-	root = btrfs_read_fs_root(fs_info->tree_root, location);
+	root = btrfs_read_tree_root(fs_info->tree_root, location);
 	if (IS_ERR(root))
 		return root;
 

fs/btrfs/disk-io.h

@@ -60,8 +60,6 @@ int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
 					struct btrfs_key *key);
-struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
-				      struct btrfs_key *location);
 int btrfs_init_fs_root(struct btrfs_root *root);
 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 					u64 root_id);