get current uptime correctly

src/fsfw/devicehandlers/DeviceHandlerBase.cpp

@@ -377,6 +377,8 @@ void DeviceHandlerBase::doStateMachine() {
         setMode(MODE_OFF);
         break;
       }
+      uint32_t currentUptime;
+      Clock::getUptime(&currentUptime);
       if (currentUptime - timeoutStart >= powerSwitcher->getSwitchDelayMs()) {
         triggerEvent(MODE_TRANSITION_FAILED, PowerSwitchIF::SWITCH_TIMEOUT, 0);
         setMode(MODE_ERROR_ON);