8268602: a couple runtime/os tests don't check exit code

Reviewed-by: dholmes

Author: iignatev

test/hotspot/jtreg/runtime/os/AvailableProcessors.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 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
@@ -87,6 +87,7 @@ public static void main(String[] args) throws Exception {
                 System.out.println("Final command line: " +
                                    ProcessTools.getCommandLine(pb));
                 OutputAnalyzer output = ProcessTools.executeProcess(pb);
+                output.shouldHaveExitValue(0);
                 output.shouldContain(SUCCESS_STRING);
             }
         }

test/hotspot/jtreg/runtime/os/TestUseCpuAllocPath.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
@@ -47,6 +47,7 @@ public static void main(String[] args) throws Exception {
                                                   "-version");
 
         OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        output.shouldHaveExitValue(0);
         output.shouldContain(SUCCESS_STRING);
     }
 }