Fix LibOverride bug when clearing invalid liboverride data.

Do not try to check liboverride properties on a freed liboverride
data.

Found while investigating #132075.

source/blender/blenkernel/intern/lib_override.cc

@@ -4372,6 +4372,7 @@ void BKE_lib_override_library_validate(Main *bmain, ID *id, ReportList *reports)
    * properly 'liboverride embedded' IDs, like root node-trees, or shape-keys. */
   if (!override_library_is_valid(*liboverride_id, *liboverride, reports)) {
     BKE_lib_override_library_make_local(nullptr, liboverride_id);
+    return;
   }
 
   override_library_properties_validate(*liboverride_id, *liboverride, reports);