Fix CoreAudio warnings in 10.6 toolchain

Signed-off-by: falkTX <falktx@gmail.com>

distrho/src/CoreAudio106/AudioUnits/AUPublic/AUBase/AUBase.cpp

@@ -186,7 +186,7 @@ void	AUBase::SetMaxFramesPerSlice(UInt32 nFrames)
 //
 OSStatus			AUBase::CanSetMaxFrames() const
 {
-	return IsInitialized() ? kAudioUnitErr_Initialized : OSStatus(noErr);
+	return IsInitialized() ? static_cast<OSStatus>(kAudioUnitErr_Initialized) : OSStatus(noErr);
 }
 
 //_____________________________________________________________________________

distrho/src/CoreAudio106/AudioUnits/AUPublic/AUBase/AUDispatch.cpp

@@ -332,7 +332,7 @@ OSStatus		AUBase::ComponentEntryDispatch(ComponentParameters *params, AUBase *Th
 			PARAM(AudioUnitScope, pinScope, 1, 4);
 			PARAM(AudioUnitElement, pinElement, 2, 4);
 			PARAM(AudioUnitParameterValue *, poutValue, 3, 4);
-			result = (poutValue == NULL ? paramErr : This->GetParameter(pinID, pinScope, pinElement, *poutValue));
+			result = (poutValue == NULL ? static_cast<OSStatus>(paramErr) : This->GetParameter(pinID, pinScope, pinElement, *poutValue));
 		}
 		break;