found memory leak in function libpff_folder_determine_

[gxiGpf]

I found descriptor_index_value in libpff_folder_determine_sub_folders, libpff_folder_determine_sub_messages, libpff_folder_determine_sub_associated_contents function may not have been released.
It may be necessary to add the following code to the return

	if( descriptor_index_value != NULL )
	{
		libpff_index_value_free(
		 &descriptor_index_value,
		 NULL );
	}