remove LWIP_THREAD_MAGIC assert in LwIP porting.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1153 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/net/lwip/src/arch/sys_arch.c

@@ -263,12 +263,8 @@ struct sys_timeouts *sys_arch_timeouts(void)
 	rt_thread_t self = rt_thread_self();
 	struct lwip_thread* lwip_th = (struct lwip_thread*)self->user_data;
 
-	if (lwip_th != RT_NULL)
-	{
-		RT_ASSERT(lwip_th->magic == LWIP_THREAD_MAGIC);
-
+	if ((lwip_th != RT_NULL) && (lwip_th->magic == LWIP_THREAD_MAGIC))
 		return &(lwip_th->timeouts);
-	}
 
 	return RT_NULL;
 }