REFAC: Change internal computation and use of LabelList for contingency.

Modules/Learning/Unsupervised/include/otbContingencyTable.h

@@ -51,7 +51,7 @@ public:
 
   MatrixType matrix;
 
-  void SetLabels(LabelList referenceLabels, LabelList producedLabels)
+  void SetLabels(const LabelList &referenceLabels, const LabelList &producedLabels)
   {
     m_RefLabels = referenceLabels;
     m_ProdLabels = producedLabels;

Modules/Learning/Unsupervised/include/otbContingencyTableCalculator.txx

@@ -107,11 +107,8 @@ ContingencyTableCalculator<TClassLabel>
   unsigned int rows = static_cast<unsigned int>(m_NumberOfRefClasses);
   unsigned int cols = static_cast<unsigned int>(m_NumberOfProdClasses);
 
-  std::vector<TClassLabel> referenceLabels;
-  std::vector<TClassLabel> producedLabels;
-
-  std::copy(refLabels.begin(), refLabels.end(), std::back_inserter(referenceLabels));
-  std::copy(prodLabels.begin(), prodLabels.end(), std::back_inserter(producedLabels));
+  std::vector<TClassLabel> referenceLabels(refLabels.begin(), refLabels.end());
+  std::vector<TClassLabel> producedLabels(prodLabels.begin(), prodLabels.end());
 
   ContingencyTablePointerType contingencyTable = ContingencyTableType::New();
   contingencyTable->SetLabels(referenceLabels, producedLabels);