message: Fix compiler error with old HYPRE
diff: @@ -2162,15 +2162,15 @@ void HypreParMatrix::DropSmallEntries(double tol)
  #elif MFEM_HYPRE_VERSION < 21800
  HYPRE_Int err_flag = hypre_ParCSRMatrixDropSmallEntries(A, tol);
  + MFEM_VERIFY(!err_flag, "error encountered: error code = " << err_flag);
  #else
  HYPRE_Int err_flag = hypre_ParCSRMatrixDropSmallEntries(A, tol, 2);
  + MFEM_VERIFY(!err_flag, "error encountered: error code = " << err_flag);
  #endif
  - MFEM_VERIFY(!err_flag, "error encountered: error code = " << err_flag);
  -
  hypre_error_flag = old_err;
  }
  