Makefile: exit on failure

Signed-off-by: Carmen Bianca BAKKER <[email protected]>

Makefile

@@ -45,11 +45,11 @@ clean-docs: ## remove docs build artifacts
 
 .PHONY: reuse
 reuse: dist ## check with self
-	poetry run reuse lint
+	poetry run reuse lint || exit 1
 	tar -xf dist/reuse*.tar.gz -C dist/
 	# This prevents the linter from using the project root as root.
 	git init dist/reuse*/
-	poetry run reuse --root dist/reuse*/ lint
+	poetry run reuse --root dist/reuse*/ lint || exit 1
 
 .PHONY: lint-third-party
 lint-third-party: ## Lint selected third-party repositories to compare with expected output