[2cstokes2p2c] Use new fluxVars facility

dumux/multidomain/2cstokes2p2c/stokesnccouplinglocalresidual.hh

@@ -137,12 +137,13 @@ public:
                         continue;
 
                     const int boundaryFaceIdx = this->fvGeometry_().boundaryFaceIndex(fIdx, faceVertexIdx);
-                    const FluxVariables boundaryVars(this->problem_(),
-                                                     this->element_(),
-                                                     this->fvGeometry_(),
-                                                     boundaryFaceIdx,
-                                                     this->curVolVars_(),
-                                                     true);
+                    FluxVariables boundaryVars;
+                    boundaryVars.update(this->problem_(),
+                                        this->element_(),
+                                        this->fvGeometry_(),
+                                        boundaryFaceIdx,
+                                        this->curVolVars_(),
+                                        true);
                     const VolumeVariables &volVars = this->curVolVars_()[scvIdx];
 
                     // set velocity normal to the interface