Improved valgrind setup [skip ci]

Author: ankane

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
 
       - run: |
           sudo apt-get install valgrind
-          valgrind --leak-check=yes build/test
+          valgrind --leak-check=yes --error-exitcode=1 build/test
 
       # test install
       - run: rm -r build