Check trackParameters for nullptr, fix for ATR-26166
Add a nullptr check to InDet::SiTrajectoryElement_xk::trackSimpleStateOnSurface. Note that this matches the protection in InDet::SiTrajectoryElement_xk::trackStateOnSurface.
Add a nullptr check to InDet::SiTrajectoryElement_xk::trackSimpleStateOnSurface. Note that this matches the protection in InDet::SiTrajectoryElement_xk::trackStateOnSurface.