putting update of water injection mobility to a separate function

computeInjectionMobility() in BlackoilPolymerModel

opm/polymer/fullyimplicit/BlackoilPolymerModel.hpp

@@ -227,6 +227,10 @@ namespace Opm {
         computeAccum(const SolutionState& state,
                      const int            aix  );
 
+        void
+        computeInjectionMobility(const SolutionState& state,
+                                 std::vector<ADB>& mob_perfcells);
+
         void
         assembleMassBalanceEq(const SolutionState& state);