Fix a bug when transferring the parameters of mass and stiffness FPM as ChMatrixNM<>
Fix a bug when transferring the parameters of mass and stiffness FPM as ChMatrixNM<>

dariomangoni/chrono,dariomangoni/chrono,rserban/chrono,projectchrono/chrono,dariomangoni/chrono,dariomangoni/chrono,rserban/chrono,rserban/chrono,dariomangoni/chrono,rserban/chrono,rserban/chrono,rserban/chrono,projectchrono/chrono,projectchrono/chrono,projectchrono/chrono,projectchrono/chrono,rserban/chrono,projectchrono/chrono,dariomangoni/chrono