dbus: Fix breakage from godbus changing *dbus.Object to dbus.BusObject interface.
dbus: Fix breakage from godbus changing *dbus.Object to dbus.BusObject interface.

pcarranzav/go-systemd,jareksm/go-systemd,dnaeon/go-systemd,mikkeloscar/go-systemd,faiq/go-systemd,endocode/go-systemd,jonboulle/go-systemd,faiq/go-systemd,mikkeloscar/go-systemd,glerchundi/go-systemd,Yhgenomics/go-systemd,pcarranzav/go-systemd,brnv/go-systemd,brnv/go-systemd,dnaeon/go-systemd,coreos/go-systemd,Yhgenomics/go-systemd,endocode/go-systemd,coreos/go-systemd,glerchundi/go-systemd,jonboulle/go-systemd,ZeissS/go-systemd,jareksm/go-systemd,ZeissS/go-systemd