journal: unbreak sd_journal_sendv

Borked since
commit 3ee897d6
Author: Lennart Poettering <lennart@poettering.net>
Date:   Wed Sep 23 01:00:04 2015 +0200

    tree-wide: port more code to use send_one_fd() and receive_one_fd()

because here our fd is not connected and we need to specify
the address.