Fix scope of the try block

Author: txominpelu

test/hotspot/jtreg/serviceability/dcmd/thread/PrintMountedVirtualThread.java

@@ -44,11 +44,11 @@ public void run(CommandExecutor executor) throws InterruptedException {
         var shouldFinish = new AtomicBoolean(false);
         var started = new CountDownLatch(1);
         final Runnable runnable = new DummyRunnable(shouldFinish, started);
-        Thread vthread = Thread.ofVirtual().name("Dummy Vthread").start(runnable);
-        started.await();
-        /* Execute */
-        OutputAnalyzer output = executor.execute("Thread.print");
         try {
+            Thread vthread = Thread.ofVirtual().name("Dummy Vthread").start(runnable);
+            started.await();
+            /* Execute */
+            OutputAnalyzer output = executor.execute("Thread.print");
             output.shouldMatch(".*at " + Pattern.quote(DummyRunnable.class.getName()) + "\\.run.*");
             output.shouldMatch(".*at " + Pattern.quote(DummyRunnable.class.getName()) + "\\.compute.*");
             output.shouldMatch("Mounted virtual thread " + "\"Dummy Vthread\"" + " #" + vthread.threadId());