stagefright: fix prvalue handling in Mutexed

    class Locked {

    public:

        inline Locked(Mutexed<T> &mParent);

        inline Locked(Locked &&from) :

            mLock(from.mLock),

            mTreasure(from.mTreasure),

            mLocked(from.mLocked) {}

        inline ~Locked();

        // dereference the protected structure. This returns nullptr if the

    // Lock the mutex, and create an accessor-guard (a Locked object) to access the underlying

    // structure. This returns an object that dereferences to the wrapped structure when the mutex

    // is locked by it, or otherwise to "null".

    inline Locked&& lock() {

        // use rvalue as Locked has no copy constructor

        return std::move(Locked(*this));

    // This is just a shorthand for Locked() constructor to avoid specifying the template type.

    inline Locked lock() {

        return Locked(*this);

    }

private:

      mTreasure(mParent.mTreasure),

      mLocked(true) {

    mLock.lock();

}

template<typename T>