systemd: Remove /var/log/journal

If `/var/log/journal` is present, systemd-journald flushes the log to
the disk, which we do not want yet, as we still use syslog. Therefore,
remove the directory.

We probably had manually deleted it on all systems with systemd 237, and
didn’t update the bee file accordingly, so that the logs were kept when
updating to systemd 239.

systemd.be0

@@ -98,6 +98,9 @@ mee_install_post() {
     rm -rv ${D}/etc/systemd/system/dbus-org.freedesktop.network1.service
     rm -rv ${D}/etc/systemd/system/multi-user.target.wants/systemd-networkd.service
     rm -rv ${D}/etc/systemd/system/network-online.target.wants/systemd-networkd-wait-online.service
+
+    # Remove directory to disable persistent storage of logs
+    rm -rv ${D}/var/log/journal
 }
 
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