test fmt works

Signed-off-by: tabokie <[email protected]>

.github/workflows/rust.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Format
         run: |
           make format
-          git diff --quiet || git diff
+          git diff --exit-code
       - name: Clippy
         run: make clippy
       - name: Run tests