Fix compilation of GRIB in the non-Jasper case

git-svn-id: https://svn.osgeo.org/gdal/trunk@28055 f0d54148-0727-0410-94bb-9a71ac55c965
Fix compilation error on Windows

git-svn-id: https://svn.osgeo.org/gdal/trunk@28056 f0d54148-0727-0410-94bb-9a71ac55c965