style fix

Author: mur47x111

compiler/src/jdk.graal.compiler.test/src/jdk/graal/compiler/core/test/CompilationWatchDogTest.java

@@ -137,7 +137,7 @@ public void onStuckCompilation(CompilationWatchDog watchDog, Thread watched, Com
         };
 
         CompilationWatchDog watch = CompilationWatchDog.watch(compilation, options, false, longCompilationHandler, null);
-        try (CompilationWatchDog watchScope = watch) {
+        try (CompilationWatchDog _ = watch) {
             event("start compiling");
             try (TTY.Filter _ = new TTY.Filter()) {
                 return super.getCode(installedCodeOwner, graph, forceCompile, installAsDefault, options);