Added (missing) return

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@9649 2fb0f335-1f38-0410-981e-8018bf24f1b0

dumux/boxmodels/2p2cni/2p2cnivolumevariables.hh

@@ -89,7 +89,7 @@ public:
      *        the sub-control volume.
      */
     Scalar thermalConductivity(const int phaseIdx) const
-    { FluidSystem::thermalConductivity(this->fluidState_, phaseIdx); };
+    { return FluidSystem::thermalConductivity(this->fluidState_, phaseIdx); };
 
 
 protected: