Merge pull request #2118 from yh-semmle/java-non-sync-override

Java: restrict `java/non-sync-override` to immediate overrides

java/ql/src/Likely Bugs/Concurrency/NonSynchronizedOverride.ql

@@ -56,6 +56,7 @@ where
   sup.isSynchronized() and
   not sub.isSynchronized() and
   not delegatingOverride(sub, sup) and
+  not exists(Method mid | sub.overrides(mid) and mid.overrides(sup)) and
   supSrc = sup.getDeclaringType().getSourceDeclaration()
 select sub,
   "Method '" + sub.getName() + "' overrides a synchronized method in $@ but is not synchronized.",