dbus-wait-for-jobs: change 'quiet' flag to enum

Change the 'quiet' flag to `bus_wait_for_jobs()` to an enum, so we can
select with more granularity the type of information logged.

src/firstboot/firstboot.c

@@ -1622,7 +1622,7 @@ static int reload_vconsole(sd_bus **bus) {
         if (r < 0)
                 return bus_log_parse_error(r);
 
-        r = bus_wait_for_jobs_one(w, object, false, NULL);
+        r = bus_wait_for_jobs_one(w, object, BUS_WAIT_JOBS_LOG_ERROR, NULL);
         if (r < 0)
                 return log_error_errno(r, "Failed to wait for systemd-vconsole-setup.service/restart: %m");
         return 0;