bmp280 properly cleanup if failed

src/drivers/bmp280/bmp280.cpp

@@ -669,9 +669,13 @@ start_bus(struct bmp280_bus_option &bus)
 
 	bus.dev = new BMP280(interface, bus.devpath);
 
-	if (bus.dev != nullptr && OK != bus.dev->init()) {
+	if (bus.dev == nullptr) {
+		return false;
+	}
+
+	if (OK != bus.dev->init()) {
 		delete bus.dev;
-		bus.dev = NULL;
+		bus.dev = nullptr;
 		return false;
 	}