[PATCH 0/1] MR8066: mmdevapi: Avoid race between main and notify thread.

[Bernhard Übelacker (＠bernhardu)]

The gitlab runners where showing a few flaky crashes in e.g. tests:
  dmsynth:dmsynth dmusic:dmusic winmm:midi

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58233

This patch attempts to wait at the DRV_CLOSE call for the thread to finish.