* Retire abstract llentry_free() in favor of lltable_drop_entry_queue()
   and explicit calls to RTENTRY_FREE_LOCKED()
* Use lltable_prefix_free() in arp_ifscrub to be consistent with nd6.
* Rename <lltable_|llt>_delete function to _delete_addr() to note that
   this function is used to external callers. Make this function maintain
   its own locking.
* Use lookup/unlink/clear call chain from internal callers instead of
    delete_addr.
* Fix LLE_DELETED flag handling