8037076: Check constant pool constants

Summary: Fix events log string.
Reviewed-by: kvn, mschoene

src/share/vm/utilities/events.cpp

 /*
- * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, 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
@@ -82,7 +82,7 @@ EventMark::EventMark(const char* format, ...) {
     va_start(ap, format);
     // Save a copy of begin message and log it.
     _buffer.printv(format, ap);
-    Events::log(NULL, _buffer);
+    Events::log(NULL, "%s", (const char*)_buffer);
     va_end(ap);
   }
 }
@@ -91,6 +91,6 @@ EventMark::~EventMark() {
   if (LogEvents) {
     // Append " done" to the begin message and log it
     _buffer.append(" done");
-    Events::log(NULL, _buffer);
+    Events::log(NULL, "%s", (const char*)_buffer);
   }
 }