systemctl: only fall back to local cgroup display if we talk to local systemd

Otherwise we likely show rubbish because even in local containers we
nowadays have cgroup namespacing, hence we likely can't access the
cgroup tree from the host at the same place as inside the container.

src/systemctl/systemctl-show.c

@@ -713,7 +713,7 @@ static void print_status_info(
                 c = LESS_BY(columns(), strlen(prefix));
 
                 r = unit_show_processes(bus, i->id, i->control_group, prefix, c, get_output_flags(), &error);
-                if (r == -EBADR) {
+                if (r == -EBADR && arg_transport == BUS_TRANSPORT_LOCAL) {
                         unsigned k = 0;
                         pid_t extra[2];