DataSource: implement missing GetLabel method (#682)

* GenericParameters: update comment

* DataSource add missing GetLabel override

* Make comment more generic

Co-authored-by: Juan Miguel Carceller <22276694+jmcarcell@users.noreply.github.com>
---------

Co-authored-by: Juan Miguel Carceller <22276694+jmcarcell@users.noreply.github.com>

include/podio/DataSource.h

@@ -85,6 +85,10 @@ class DataSource : public ROOT::RDF::RDataSource {
   ///
   std::string GetTypeName(std::string_view columnName) const override;
 
+  std::string GetLabel() override {
+    return "PODIO Datasource";
+  };
+
 protected:
   ///
   /// @brief Type-erased vector of pointers to pointers to column

src/GenericParameters.cc

@@ -17,7 +17,7 @@ GenericParameters::GenericParameters(const GenericParameters& other) :
     m_stringMtx(std::make_unique<std::mutex>()),
     m_doubleMtx(std::make_unique<std::mutex>()) {
   {
-    // acquire all three locks at once to make sure all three internal maps are
+    // acquire all locks at once to make sure all internal maps are
     // copied at the same "state" of the GenericParameters
     auto& intMtx = other.getMutex<int>();
     auto& floatMtx = other.getMutex<float>();