update-kernel: Fix free -> g_object_unref
update-kernel: Fix free -> g_object_unref

sujitfulse/ostree,resin-io/ostree,resin-io/ostree,resin-io/ostree,GNOME/ostree,GNOME/ostree,leandrosansilva/ostree,leandrosansilva/ostree,leandrosansilva/ostree,sujitfulse/ostree,gatispaeglis/ostree,leandrosansilva/ostree,gatispaeglis/ostree,leandrosansilva/ostree,sujitfulse/ostree,GNOME/ostree,gatispaeglis/ostree,gatispaeglis/ostree,GNOME/ostree,sujitfulse/ostree,sujitfulse/ostree,resin-io/ostree,GNOME/ostree,gatispaeglis/ostree,resin-io/ostree,gatispaeglis/ostree