output raw diff

Author: wxiaoguang

Makefile

@@ -463,7 +463,7 @@ tidy-check: tidy
 	@diff=$$(git diff --color=always go.mod go.sum $(GO_LICENSE_FILE)); \
 	if [ -n "$$diff" ]; then \
 		echo "Please run 'make tidy' and commit the result:"; \
-		echo "$${diff}"; \
+		printf "%s" "$${diff}"; \
 		exit 1; \
 	fi