[Bug 36784] valgrind shows a leak in kernel32/tests/thread.c

https://bugs.winehq.org/show_bug.cgi?id=36784

--- Comment #2 from Austin English  ---
With the patch:
==29913== 68 bytes in 1 blocks are definitely lost in loss record 137 of 285
==29913==    at 0x7BC49369: notify_alloc (heap.c:255)
==29913==    by 0x7BC4D59F: RtlAllocateHeap (heap.c:1716)
==29913==    by 0x7BC31C49: RtlCreateActivationContext (actctx.c:4506)
==29913==    by 0x7B827493: CreateActCtxW (actctx.c:124)
==29913==    by 0x4E368BD: test_create (thread.c:1521)
==29913==    by 0x4E36BE1: test_thread_actctx (thread.c:1554)
==29913==    by 0x4E378E8: func_thread (thread.c:1777)
==29913==    by 0x4E53836: run_test (test.h:584)
==29913==    by 0x4E53C02: main (test.h:654)
==29913==