Make it work on Travis Mac and mingw

git-svn-id: https://svn.osgeo.org/gdal/trunk@27388 f0d54148-0727-0410-94bb-9a71ac55c965
Compilation fix with MSVC

git-svn-id: https://svn.osgeo.org/gdal/trunk@27389 f0d54148-0727-0410-94bb-9a71ac55c965