Use std::min to calculate startFrame

Co-authored-by: Dominic Clark <mrdomclark@gmail.com>

src/core/Instrument.cpp

@@ -186,7 +186,7 @@ void Instrument::applyRelease( SampleFrame* buf, const NotePlayHandle * _n )
 	const auto releaseFrames = desiredReleaseFrames();
 
 	const auto endFrame = _n->framesLeft();
-	const auto startFrame = std::max(0, static_cast<int>(endFrame) - static_cast<int>(releaseFrames));
+	const auto startFrame = endFrame - std::min(endFrame, releaseFrames);
 
 	for (auto f = startFrame; f < endFrame && f < fpp; f++)
 	{