fix check for cartesian communicator

include/ALL.hpp

@@ -200,7 +200,8 @@ public:
   /// @param[in] comm the communicator to be used
   void setCommunicator(const MPI_Comm comm) {
     int comm_type;
-    if (MPI_Topo_test(comm, &comm_type) == MPI_CART) {
+    MPI_Topo_test(comm, &comm_type);
+    if ( comm_type == MPI_CART) {
       communicator = comm;
       balancer->setCommunicator(communicator);
     } else {