context protocol destroy provide nonnull wsi with context

Signed-off-by: Andy Green <andy.green@linaro.org>

lib/context.c

@@ -253,6 +253,7 @@ LWS_VISIBLE void
 lws_context_destroy(struct lws_context *context)
 {
 	const struct lws_protocols *protocol = NULL;
+	struct lws wsi;
 	int n;
 
 	lwsl_notice("%s\n", __func__);
@@ -260,6 +261,9 @@ lws_context_destroy(struct lws_context *context)
 	if (!context)
 		return;
 
+	memset(&wsi, 0, sizeof(wsi));
+	wsi.context = context;
+
 #ifdef LWS_LATENCY
 	if (context->worst_latency_info[0])
 		lwsl_notice("Worst latency: %s\n", context->worst_latency_info);
@@ -292,7 +296,7 @@ lws_context_destroy(struct lws_context *context)
 	protocol = context->protocols;
 	if (protocol) {
 		while (protocol->callback) {
-			protocol->callback(NULL,
+			protocol->callback(&wsi,
 					   LWS_CALLBACK_PROTOCOL_DESTROY,
 					   NULL, NULL, 0);
 			protocol++;