Fix initialisation warning.

opm/core/linalg/LinearSolverUmfpack.cpp

@@ -56,7 +56,7 @@ namespace Opm
             const_cast<double*>(sa)
         };
         call_UMFPACK(&A, rhs, solution);
-        LinearSolverReport rep = {0};
+        LinearSolverReport rep = {};
         rep.converged = true;
         return rep;
     }