renaming and adding more comments based on review

opm/simulators/wells/GasLiftGroupInfo.hpp

@@ -196,6 +196,8 @@ protected:
             gas_rate_ += delta_gas;
             water_rate_ += delta_water;
             alq_ += delta_alq;
+            // Note. We don't updata the potentials at this point. They
+            // are only needed initially.
         }
     private:
         double oil_rate_;