message: helper: Remove unnecessary condition from Comm MPI implementation
  The source file is built only when MPI is available, so we do not need
  to test for that inside the source.
diff: @@ -378,7 +378,6 @@ Comm::Status CommImplMPI::Recv(void *buf, size_t count, Datatype datatype,
  hint);
  Comm::Status status;
  -#ifdef ADIOS2_HAVE_MPI
  status.Source = mpiStatus.MPI_SOURCE;
  status.Tag = mpiStatus.MPI_TAG;
  {
  @@ -387,7 +386,6 @@ Comm::Status CommImplMPI::Recv(void *buf, size_t count, Datatype datatype,
  hint);
  status.Count = mpiCount;
  }
  -#endif
  return status;
  }
  @@ -514,7 +512,6 @@ Comm::Status CommReqImplMPI::Wait(const std::string &hint)
  return status;
  }
  -#ifdef ADIOS2_HAVE_MPI
  std::vector<MPI_Request> mpiRequests = std::move(m_MPIReqs);
  std::vector<MPI_Status> mpiStatuses(mpiRequests.size());
  @@ -564,7 +561,6 @@ Comm::Status CommReqImplMPI::Wait(const std::string &hint)
  break;
  }
  }
  -#endif
  return status;
  }
  