Revert "Fixed deadlock in CRYPTO_THREAD_run_once for Windows"

This reverts commit edc18749

.

The proposed fix is incorrect. It marks the "run_once" code as having
finished before it has. The intended semantics of run_once is that no
threads should proceed until the code has run exactly once. With this
change the "second" thread will think the run_once code has already been
run and will continue, even though it is still in progress. This could
result in a crash or other incorrect behaviour.

Reviewed-by: Tim Hudson <tjh@openssl.org>