Fix recursion issue in InDetSecVertexValidation

Sometimes (rarely) decays will be created with loops in the particle records in the decays of BSM particles, and when that occurs, descendent particles can be added recursively an infinite amount of times, leading to a stack overflow and crash. This is a MR to fix that case in InDetSecVertexTruthMatchTool:countReconstructibleDescendentPartitcles

InnerDetector/InDetValidation/InDetSecVertexValidation/InDetSecVertexValidation/InDetSecVertexTruthMatchTool.h

@@ -101,7 +101,7 @@ class InDetSecVertexTruthMatchTool : public virtual IInDetSecVertexTruthMatchToo
   //returns barcode of LLP production truth vertex
   int checkProduction( const xAOD::TruthParticle& truthPart ) const;
   void countReconstructibleDescendentParticles(const xAOD::TruthVertex& signalTruthVertex,
-                                               std::vector<const xAOD::TruthParticle*>& set) const;
+                                               std::vector<const xAOD::TruthParticle*>& set, int counter) const;
   std::vector<int> checkParticle( const xAOD::TruthParticle& part, const xAOD::TrackParticleContainer &tkCont ) const;
 
   // (optional) write out histograms