Remove unneeded intermediate async for Ethernet (#1864)

Remove the always pending worker whose job it was to fire another async
worker after a timeout.

libraries/lwIP_Ethernet/src/LwipEthernet.cpp

@@ -31,7 +31,6 @@ bool __ethernetContextInitted = false;
 
 // Async context that pumps the ethernet controllers
 static async_context_threadsafe_background_t lwip_ethernet_async_context_threadsafe_background;
-static async_when_pending_worker_t always_pending_update_timeout_worker;
 static async_at_time_worker_t ethernet_timeout_worker;
 
 static async_context_t *_context = nullptr;
@@ -129,8 +128,9 @@ static async_context_t *lwip_ethernet_init_default_async_context(void) {
     return NULL;
 }
 
+static uint32_t _pollingPeriod = 20;
 // This will only be called under the protection of the async context mutex, so no re-entrancy checks needed
-static void ethernet_timeout_reached(__unused async_context_t *context, __unused async_at_time_worker_t *worker) {
+static void ethernet_timeout_reached(async_context_t *context, __unused async_at_time_worker_t *worker) {
     assert(worker == &ethernet_timeout_worker);
     for (auto handlePacket : _handlePacketList) {
         handlePacket.second();
@@ -142,12 +142,6 @@ static void ethernet_timeout_reached(__unused async_context_t *context, __unused
 #else
     sys_check_timeouts();
 #endif
-}
-
-static uint32_t _pollingPeriod = 20;
-static void update_next_timeout(async_context_t *context, async_when_pending_worker_t *worker) {
-    assert(worker == &always_pending_update_timeout_worker);
-    worker->work_pending = true;
     async_context_add_at_time_worker_in_ms(context, &ethernet_timeout_worker, _pollingPeriod);
 }
 
@@ -164,10 +158,8 @@ void __startEthernetContext() {
 #else
     _context = lwip_ethernet_init_default_async_context();
 #endif
-    always_pending_update_timeout_worker.work_pending = true;
-    always_pending_update_timeout_worker.do_work = update_next_timeout;
     ethernet_timeout_worker.do_work = ethernet_timeout_reached;
-    async_context_add_when_pending_worker(_context, &always_pending_update_timeout_worker);
+    async_context_add_at_time_worker_in_ms(_context, &ethernet_timeout_worker, _pollingPeriod);
     __ethernetContextInitted = true;
 }