Migrate G4UserActions and TrackWriteFastSim packages to use (Const)GenParticlePtr

Simulation/G4Utilities/G4UserActions/src/AthenaTrackingAction.cxx

@@ -46,8 +46,8 @@ namespace G4UA
     {
       // Why a const_cast???
       // This is an ugly way to communicate the GenParticle...
-      HepMC::GenParticle* part =
-        const_cast<HepMC::GenParticle*>( trackHelper.GetTrackInformation()->
+      HepMC::GenParticlePtr part =
+        const_cast<HepMC::GenParticlePtr>( trackHelper.GetTrackInformation()->
                                          GetHepMCParticle() );
 
       // Assign the GenParticle to the EventInformation.

Simulation/G4Utilities/TrackWriteFastSim/src/NeutronFastSim.cxx

@@ -51,7 +51,7 @@ G4bool NeutronFastSim::ModelTrigger(const G4FastTrack& fastTrack)
 
   // Not a neutron... Pick it up if the primary had eta>6.0
   EventInformation *eventInfo=static_cast<EventInformation*>(G4EventManager::GetEventManager()->GetConstCurrentEvent()->GetUserInformation());
-  HepMC::GenParticle *gp = eventInfo->GetCurrentPrimary();
+  HepMC::GenParticlePtr gp = eventInfo->GetCurrentPrimary();
   if (fabs(gp->momentum().eta())>m_etaCut && gp->barcode()<200000){
     return true;
   } else {