MySQL uses _beginthread()/_endthread() instead of 
_beginthreadex()/_endthreadex() to create/end its threads
on Windows.
According to MSDN  _endthread() does close the thread handle.
So there's no need the handle to be closed explicitly.
Besides : WaitForSingleObject(, INFINITE) != WAIT_OBJECT_0) is
true for all practical cases as the other two possible return 
codes (according to MSDN) cannot happen in that case the 
CloseHandle() was actually a dead code.
Fixed by removing the CloseHandle() call. No test case added
because it's not possible to test for absence of dead code. 


include/my_pthread.h:
  Bug #26564: Don't call CloseHandle since we use 
  beginthread/endthread instead of beginthreadex/endthreadex.