Guard OpenMP-related calls for GPU_MPI with the preprocessor.
Guard OpenMP-related calls for GPU_MPI with the preprocessor.

evaneschneider/cholla,evaneschneider/cholla,cholla-hydro/cholla,evaneschneider/cholla,evaneschneider/cholla,cholla-hydro/cholla,cholla-hydro/cholla,cholla-hydro/cholla