False uninit reports under StackTraceW

_From [timurrrr@google.com](https://code.google.com/u/timurrrr@google.com/) on September 15, 2010 10:46:05_

I see the following stacks when running Chromium
TraceEventTest.TraceLog from base_unittests ( r59494 )
under Dr. Memory r46 : (formatted as a suppression)

UNINITIALIZED READ: reading 0x0012d898-0x0012d89c 4 byte(s)
ADVAPI32.dll!WmiMofEnumerateResourcesA
ADVAPI32.dll!WmiMofEnumerateResourcesA
ADVAPI32.dll!StackTraceW
*!EtwTraceController::Start
*!EtwTraceController::Start
*!`anonymous namespace'::TraceEventTest::SetUp

I've run this test under debugger and I can clearly see
that 0x0012d898 is rewritten from '\0' to '<' while ESP value at the upper "EtwTraceController::Start" is 0x0012da60.

I couldn't reproduce a similar report using the example from MSDN yet: http://msdn.microsoft.com/en-us/library/ee441323(v=VS.85).aspx

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=53_