BNA, KML: fix segfault when calling GetNextFeature() on a write-only layer

git-svn-id: https://svn.osgeo.org/gdal/trunk@27886 f0d54148-0727-0410-94bb-9a71ac55c965
MITAB: fix memleak in error code path of ParseTABFileFields()

git-svn-id: https://svn.osgeo.org/gdal/trunk@27887 f0d54148-0727-0410-94bb-9a71ac55c965