This function was factored out in 57d0b1e2ea (files-backend: extract out
`create_symref_lock()`, 2024-05-07), but we never look at the ref_store
or refname parameters. We just need the path, which is already contained
in the lockfile struct.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>