Merge pull request #711 from cpanato/update-makefile

makefile: update makefile verify-modules

Author: k8s-ci-robot

Makefile

@@ -462,7 +462,7 @@ verify-boilerplate:
 
 .PHONY: verify-modules
 verify-modules: modules
-	@if !(git diff --quiet HEAD -- go.sum go.mod hack/tools/go.mod hack/tools/go.sum); then \
+	@if !(git diff --quiet HEAD -- go.sum go.mod); then \
 		echo "go module files are out of date"; exit 1; \
 	fi