MuonG4SD: fix thread-checker warning

MuonSpectrometer/MuonG4/MuonG4SD/src/MDTSensitiveDetectorCosmics.cxx

@@ -156,7 +156,7 @@ G4bool MDTSensitiveDetectorCosmics::ProcessHits(G4Step* aStep,G4TouchableHistory
   if( ((nameSD) && (namePreStepMat != namePostStepMat)) || (currentTrack->GetTrackStatus() ==  fStopAndKill)){
 
     // get identifier
-    G4TouchableHistory* touchHist = (G4TouchableHistory*)aStep->GetPreStepPoint()->GetTouchable();
+    const G4TouchableHistory* touchHist = static_cast<const G4TouchableHistory*>(aStep->GetPreStepPoint()->GetTouchable());
     int MDTid = GetIdentifier(touchHist);
 
     TrackHelper trHelp(aStep->GetTrack());
@@ -173,7 +173,7 @@ G4bool MDTSensitiveDetectorCosmics::ProcessHits(G4Step* aStep,G4TouchableHistory
   return true;
 }
 
-int MDTSensitiveDetectorCosmics::GetIdentifier(G4TouchableHistory* touchHist)
+int MDTSensitiveDetectorCosmics::GetIdentifier(const G4TouchableHistory* touchHist)
 {
   // attributes of the MDT identifier construction
   std::string stationName;

MuonSpectrometer/MuonG4/MuonG4SD/src/MDTSensitiveDetectorCosmics.h

@@ -101,7 +101,7 @@ public:
     G4bool ProcessHits(G4Step* aStep, G4TouchableHistory* ROhist) override final;
     
 private:
-    int  GetIdentifier(G4TouchableHistory* touchHist);
+    int  GetIdentifier(const G4TouchableHistory* touchHist);
     Amg::Vector3D m_mom;           
     double m_momMag;           
     Amg::Vector3D m_vertex;