tree-wide: do not print hint about -M if -M is already used

(Or when -H is used, since -H and -M are incompatible.)

Note that the slightly unusual form with separate boolean variables (hint_vars,
hint_addr) instead of e.g. a const char* variable to hold the message, because this
way we don't trigger the warning about non-literal format.

src/systemctl/systemctl-util.c

@@ -53,7 +53,7 @@ int acquire_bus(BusFocus focus, sd_bus **ret) {
                 else
                         r = bus_connect_transport(arg_transport, arg_host, user, &buses[focus]);
                 if (r < 0)
-                        return bus_log_connect_error(r);
+                        return bus_log_connect_error(r, arg_transport);
 
                 (void) sd_bus_set_allow_interactive_authorization(buses[focus], arg_ask_password);
         }