OGRLayer: Update(): avoid creating features with null or empty geometry (#4772)

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@25428 f0d54148-0727-0410-94bb-9a71ac55c965
Fix typo [ci skip]

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@25429 f0d54148-0727-0410-94bb-9a71ac55c965