8271093: remove deadcode from runtime/Thread/TestThreadDumpSMRInfo.java test

Reviewed-by: jiefu, dholmes, dcubed

Author: iignatev

test/hotspot/jtreg/runtime/Thread/TestThreadDumpSMRInfo.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -85,9 +85,4 @@ public static void main(String[] args) throws Exception {
 
         System.out.println("Test PASSED.");
     }
-
-    static void usage() {
-        System.err.println("Usage: java TestThreadDumpSMRInfo [-v]");
-        System.exit(1);
-    }
 }