binding: navigation: move get_storage_from_value call within write lock

json_object returned from get_storage_from_value() needs to be protected
within the write lock. This is to prevent reentrant calls to broadcast() from
accessing it, and running json_object_put()

Bug-AGL: SPEC-2880
Change-Id: I9fdf614728368c75e925e4c5a0f3ca19a7e517e1
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>

binding/navigation-api.c

@@ -135,10 +135,12 @@ static void broadcast(afb_req_t request, const char *name, gboolean cache)
 	json_object *jresp = afb_req_json(request);
 
 	if (cache) {
-		json_object **storage = get_storage_from_value(ns, name);
+		json_object **storage;
 
 		g_rw_lock_writer_lock(&ns->rw_lock);
 
+		storage = get_storage_from_value(ns, name);
+
 		if (*storage)
 			json_object_put(*storage);