Fix empty version output in release builds

Author: mdbooth

Makefile

@@ -282,7 +282,7 @@ generate-manifests: $(CONTROLLER_GEN) ## Generate manifests e.g. CRD, RBAC etc.
 
 .PHONY: docker-build
 docker-build: ## Build the docker image for controller-manager
-	docker build -f Dockerfile --build-arg goproxy=$(GOPROXY) --build-arg ARCH=$(ARCH) --build-arg LDFLAGS="$(LDFLAGS)" . -t $(CONTROLLER_IMG_TAG)
+	docker build -f Dockerfile --build-arg goproxy=$(GOPROXY) --build-arg ARCH=$(ARCH) --build-arg ldflags="$(LDFLAGS)" . -t $(CONTROLLER_IMG_TAG)
 
 .PHONY: docker-push
 docker-push: ## Push the docker image