systemd: rework machine-idd service

- always set a *valid* machine-id
- start machine-id.service before journald

packages/sysutils/systemd/scripts/systemd-machine-id-setup

@@ -34,8 +34,6 @@ elif [ -e "/sys/class/net/wlan0/address" ]; then
   MAC_ADRESS=`cat /sys/class/net/wlan0/address`
 fi
 
-if [ -n "$MAC_ADRESS" ]; then
 MACHINEID=`echo $MAC_ADRESS | md5sum | cut -f1 -d" "`
-fi
 
 echo "$MACHINEID" > /run/machine-id

packages/sysutils/systemd/system.d/machine-id.service

@@ -2,6 +2,7 @@
 Description=Setup machine-id
 DefaultDependencies=no
 After=local-fs.target
+Before=systemd-journald.service
 
 [Service]
 Type=oneshot