Make copies basic_rates list more useful

Commit e5693c4775bae65faa960f80889f98b0a6cb2e1c added a copy of the
determined basic rate set into struct hostapd_iface, but did not
actually copy the terminating -1 value. This could be problematic if
something were to actually try to use this list since would be no way to
know what is the last entry in the list. Fix this by copying the
terminating value.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/ap/hw_features.c

@@ -129,6 +129,8 @@ int hostapd_prepare_rates(struct hostapd_iface *iface,
 	i = 0;
 	while (basic_rates[i] >= 0)
 		i++;
+	if (i)
+		i++; /* -1 termination */
 	os_free(iface->basic_rates);
 	iface->basic_rates = os_malloc(i * sizeof(int));
 	if (iface->basic_rates)