update mockgen

Signed-off-by: Yu Jiang <[email protected]>

Makefile

@@ -40,7 +40,7 @@ kubebuilder:
 	sudo cp -rf kubebuilder /usr/local
 
 mock:
-	go get -u github.com/golang/mock/mockgen
+	go install github.com/golang/mock/mockgen
 	@echo "mockgen is in progess"
 	@for pkg in $(shell go list ./...) ; do \
 		go generate ./... ;\