All the watchlist notify macros were broken in that they did not check
that the watchlist item was still valid before calling it. This only
came into play when a watchlist was being notified and one of the notify
functions removed an item from the same watchlist. It appears this was
already thought of since watchlist_remove checks 'in_notify' and will
mark the item's id as stale (0), but that id never got checked in the
notify macros.
This fixes testAdHoc valgrind warning:
==3347== Invalid read of size 4
==3347== at 0x416612: eapol_rx_auth_packet (eapol.c:1871)
==3347== by 0x416DD4: __eapol_rx_packet (eapol.c:2334)
==3347== by 0x40725B: netdev_pae_read (netdev.c:3515)
==3347== by 0x440958: io_callback (io.c:123)
==3347== by 0x43FDED: l_main_iterate (main.c:376)
==3347== by 0x43FEAB: l_main_run (main.c:423)
==3347== by 0x40377A: main (main.c:489)
...
In WATCHLIST_NOTIFY_MATCHES pass pointer to the item instead of
item->notify_data to free item->notify_data to be the final watch user's
user_data. This is also what netdev expects.
This can be used to selectively notify watchlist items. The match
function is called for each watchlist_item and match_data is passed
along. If the match function returns true, then the watch_item is
notified. The match function signature and semantics are identical
to l_queue_match_func_t.
