btrfs: remove redundant path release when replaying a log tree

There's no need to call btrfs_release_path() before calling
btrfs_init_root_free_objectid() as we have released the path already at
the top of the loop and the previous call to fixup_inode_link_counts()
also releases the path. So remove it to simplify the code.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>