TEENAGENT: Added missing lock in music player, replaced protected with private.

engines/teenagent/music.cpp

@@ -51,6 +51,7 @@ bool MusicPlayer::load(int id) {
 	stream->read(header, 4);
 	//check header?
 
+	Common::StackLock lock(_mutex);
 	// Load the samples
 	sampleCount = stream->readByte();
 

engines/teenagent/music.h

@@ -40,7 +40,7 @@ public:
 	void start();
 	void stop();
 
-protected:
+private:
 	int _id;
 
 	struct Row {