Save vvelero image tarball only for velero namespace in docker regist…

…ry (#5581)

Signed-off-by: danfengl <danfengl@vmware.com>

Makefile

@@ -209,10 +209,11 @@ endif
 	--build-arg=RESTIC_VERSION=$(RESTIC_VERSION) \
 	-f $(VELERO_DOCKERFILE) .
 	@echo "container: $(IMAGE):$(VERSION)"
-ifeq ($(BUILDX_OUTPUT_TYPE), registry)
-	@docker pull $(IMAGE):$(VERSION)
-	@docker save $(IMAGE):$(VERSION) -o $(BIN)-$(VERSION).tar
-	@gzip $(BIN)-$(VERSION).tar
+ifeq ($(BUILDX_OUTPUT_TYPE)_$(REGISTRY), registry_velero)
+	docker pull $(IMAGE):$(VERSION)
+	rm -f $(BIN)-$(VERSION).tar
+	docker save $(IMAGE):$(VERSION) -o $(BIN)-$(VERSION).tar
+	gzip -f $(BIN)-$(VERSION).tar
 endif
 
 SKIP_TESTS ?=