fix typo in examples/gui/demo_workbench.c

use RT_USING_FINSH micro to decide whether to compile FINSH functions or not.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1780 bbd45198-f89e-11dd-88c7-29a3b14d5316

examples/gui/demo_workbench.c

@@ -127,7 +127,7 @@ void workbench_init()
 	}
 }
 
-#ifdef RT_USING_RTGUI
+#ifdef RT_USING_FINSH
 #include <finsh.h>
 void workbench()
 {