MueLu: Test failures on CUDA

Created by: tjfulle

@trilinos/muelu

The following tests fail on CUDA (ride.sandia.gov, gcc 5.4, openmpi 1.10.4, cuda 8.0.44):

 158 - MueLu_Navier2DBlocked_Epetra_MPI_4 (Failed)
 159 - MueLu_Navier2DBlocked_xml_format_MPI_4 (Failed)
 160 - MueLu_Navier2DBlocked_xml_format2_MPI_4 (Failed)
 161 - MueLu_Navier2DBlocked_xml_blockdirect_MPI_4 (Failed)
 162 - MueLu_Navier2DBlocked_xml_bgs1_MPI_4 (Failed)
 163 - MueLu_Navier2DBlocked_xml_bs1_MPI_4 (Failed)
 164 - MueLu_Navier2DBlocked_xml_bs2_MPI_4 (Failed)
 165 - MueLu_Navier2DBlocked_xml_sim1_MPI_4 (Failed)
 166 - MueLu_Navier2DBlocked_xml_sim2_MPI_4 (Failed)
 167 - MueLu_Navier2DBlocked_xml_uzawa1_MPI_4 (Failed)
 168 - MueLu_Navier2DBlocked_xml_indef1_MPI_4 (Failed)
 171 - MueLu_Navier2DBlocked_BraessSarazin_MPI_4 (Failed)
 172 - MueLu_Navier2DBlockedReuseAggs_MPI_4 (Failed)
 173 - MueLu_Navier2DBlocked_Simple_MPI_4 (Failed)

All of the MueLu tests failed with the following error:

MueLu::EpetraOperator::Comm(): Cast from Xpetra::CrsMatrix to Xpetra::EpetraCrsMatrix failed