increase more stack size in demo workbench.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1150 bbd45198-f89e-11dd-88c7-29a3b14d5316

examples/gui/demo_workbench.c

@@ -116,7 +116,7 @@ void workbench_init()
 
 		tid = rt_thread_create("wb",
 			workbench_entry, RT_NULL,
-			2048, 25, 10);
+			2048 * 2, 25, 10);
 
 		if (tid != RT_NULL) rt_thread_startup(tid);