fix jcheck errors

Author: plummercj

test/hotspot/jtreg/vmTestbase/nsk/share/jdi/Debugee.java

@@ -270,13 +270,13 @@ public ThreadReference threadByNameOrThrow(String name) throws JDITestRuntimeExc
     public ThreadReference threadByFieldNameOrThrow(ReferenceType debuggeeClass,
                                                     String threadFieldName)
             throws JDITestRuntimeException {
-        
+
         Field field = debuggeeClass.fieldByName(threadFieldName);
         if (field == null) {
             throw new JDITestRuntimeException("** Thread field not found ** : "
                                               + threadFieldName);
         }
-        
+
         ThreadReference thread = (ThreadReference)debuggeeClass.getValue(field);
         if (thread == null) {
             throw new JDITestRuntimeException("** Thread field is null ** : "
@@ -287,23 +287,8 @@ public ThreadReference threadByFieldNameOrThrow(ReferenceType debuggeeClass,
             throw new JDITestRuntimeException("** Thread names do not match ** : "
                                               + threadFieldName + " vs. " + thread.name());
         }
-        
-        return thread;
-    }
 
-    public void setMainThread(ThreadReference thread) {
-        String threadName = thread.name();
-        if (!threadName.equals("main")) {
-            throw new TestBug("Thread is not \"main\" thread: " + threadName);
-        }
-        mainThread = thread;
-    }
-
-    public ThreadReference mainThread() {
-        if (mainThread == null) {
-            throw new JDITestRuntimeException("** mainThrad has not been set **");
-        }
-        return mainThread;
+        return thread;
     }
 
     // --------------------------------------------------- //