WASAPI: Don't stop the device while in the middle of rerouting.

Public issue https://github.com/mackron/miniaudio/issues/582

miniaudio.h

@@ -41247,6 +41247,9 @@ MA_API ma_result ma_device_stop(ma_device* pDevice)
         return MA_SUCCESS;  /* Already stopped. */
     }
 
+    /* Wait for any rerouting to finish before attempting to stop the device. */
+    ma_mutex_lock(&pDevice->wasapi.rerouteLock);
+    {
         ma_mutex_lock(&pDevice->startStopLock);
         {
             /* Starting and stopping are wrapped in a mutex which means we can assert that the device is in a started or paused state. */
@@ -41295,6 +41298,8 @@ MA_API ma_result ma_device_stop(ma_device* pDevice)
             pDevice->playback.inputCacheRemaining   = 0;
         }
         ma_mutex_unlock(&pDevice->startStopLock);
+    }
+    ma_mutex_unlock(&pDevice->wasapi.rerouteLock);
 
     return result;
 }