message: fix #ifdef name for nlconvection.
diff: // terms of the BSD-3 license. We welcome feedback and contributions, see file
  // CONTRIBUTING.md for details.
  -#ifndef MFEM_LIBCEED_CONV_HPP
  -#define MFEM_LIBCEED_CONV_HPP
  +#ifndef MFEM_LIBCEED_NLCONV_HPP
  +#define MFEM_LIBCEED_NLCONV_HPP
  #include "integrator.hpp"
  #include "../fespace.hpp"
  @@ -45,4 +45,4 @@ public:
  }
  -#endif // MFEM_LIBCEED_CONV_HPP
  +#endif // MFEM_LIBCEED_NLCONV_HPP
  