prefix for MUMPS parameters

AMDiS/src/parallel/PetscSolverGlobalMatrix.cc

@@ -599,6 +599,7 @@ namespace AMDiS { namespace Parallel {
     KSPSetTolerances(ksp, 0.0, 1e-8, PETSC_DEFAULT, PETSC_DEFAULT);
     KSPSetType(ksp, KSPBCGS);
     KSPSetOptionsPrefix(ksp, kspPrefix.c_str());
+    MatSetOptionsPrefix(getMatInterior(), kspPrefix.c_str());
     KSPSetFromOptions(ksp);
 
     // Do not delete the solution vector, use it for the initial guess.