Core Audio: Try fixing a compilation error.

Public issue https://github.com/mackron/miniaudio/issues/841

miniaudio.h

@@ -34196,7 +34196,7 @@ static ma_result ma_device_init_internal__coreaudio(ma_context* pContext, ma_dev
     OSStatus status;
     UInt32 enableIOFlag;
     AudioStreamBasicDescription bestFormat;
-    UInt32 actualPeriodSizeInFrames;
+    ma_uint32 actualPeriodSizeInFrames;
     AURenderCallbackStruct callbackInfo;
 #if defined(MA_APPLE_DESKTOP)
     AudioObjectID deviceObjectID;