Fix build with mingw in non-optimized mode

git-svn-id: https://svn.osgeo.org/gdal/trunk@27851 f0d54148-0727-0410-94bb-9a71ac55c965
OCI: Fix unsafe use of snprintf()

git-svn-id: https://svn.osgeo.org/gdal/trunk@27852 f0d54148-0727-0410-94bb-9a71ac55c965