AMR-Trilinos: Use reduced communicator

ippl/test/AMR/trilinos/AmrMultiGridLevel.hpp

@@ -234,5 +234,7 @@ void AmrMultiGridLevel<MatrixType, VectorType>::buildMap_m(const Teuchos::RCP<co
     // numGlobalElements == N
     int N = grids.numPts();
     
-    map_p = Teuchos::rcp( new dmap_t(N, globalindices, baseIndex, comm, node) );
+    Teuchos::RCP<dmap_t> full = Teuchos::rcp( new dmap_t(N, globalindices, baseIndex, comm, node) );
+    
+    map_p = full->removeEmptyProcesses();
 }