Function cargo::sources::registry::download::finish_download

pub(super) fn finish_download(
    cache_path: &Filesystem,
    config: &Config,
    pkg: PackageId,
    checksum: &str,
    data: &[u8]
) -> CargoResult<File>

Verifies the integrity of data with checksum and persists it under the directory at cache_path.

This is primarily called by RegistryData::finish_download.