uorb devices: set errno on write error

src/modules/uORB/uORBDevices.cpp

@@ -437,6 +437,7 @@ uORB::DeviceNode::publish(const orb_metadata *meta, orb_advert_t handle, const v
 	ret = devnode->write(nullptr, (const char *)data, meta->o_size);
 
 	if (ret < 0) {
+		errno = -ret;
 		return ERROR;
 	}