(_hurd_canonicalize_directory_name_internal): Don't deallocate DOTID & DOTDEVID...

(_hurd_canonicalize_directory_name_internal):   Don't deallocate DOTID & DOTDEVID until we're finished with them (we need     to keep them at least until we've fetched the next level of id ports, so     that mach will be able to use the same name if they're the same).   Add inner_errlose: label, which deallocates DOTID & DOTDEVID and jumps to     errlose, for those places where such cleanup is needed.