systemd/initrd-switch-root.service: call switch-root with --no-block

modules.d/98systemd/initrd-switch-root.service

@@ -11,12 +11,13 @@ DefaultDependencies=no
 ConditionPathExists=/etc/initrd-release
 OnFailure=emergency.service
 After=initrd-switch-root.target
+AllowIsolate=yes
 
 [Service]
 Type=oneshot
 EnvironmentFile=/run/initramfs/switch-root.conf
 # we have to use "--force" here, otherwise systemd would umount /run
-ExecStart=/usr/bin/systemctl --force switch-root ${NEWROOT} ${NEWINIT}
+ExecStart=-/usr/bin/systemctl --no-block --force switch-root ${NEWROOT} ${NEWINIT}
 ExecStopPost=-/bin/rm -f /run/initramfs/switch-root.conf
 StandardInput=null
 StandardOutput=null