don't blindly commit

Author: bradh352

.github/workflows/sync_upstream.yml

@@ -39,5 +39,9 @@ jobs:
           git pull
           cd ../..
           git add .
-          git commit -am "update sonic-swss and sonic-sairedis branches"
-          git push
+          if git status | grep "nothing to commit" > /dev/null ; then
+            echo "nothing to commit"
+          else
+            git commit -am "update sonic-swss and sonic-sairedis branches"
+            git push
+          fi