fix the FINSH_USING_SYMTAB not defined and compiling error issue

include/rtdef.h

@@ -204,8 +204,13 @@ typedef int (*init_fn_t)(void);
 
 #if !defined(RT_USING_FINSH)
 /* define these to empty, even if not include finsh.h file */
-#define FINSH_FUNCTION_EXPORT_CMD(name, cmd, desc)
+#define FINSH_FUNCTION_EXPORT(name, desc)
+#define FINSH_FUNCTION_EXPORT_ALIAS(name, alias, desc)
 #define FINSH_VAR_EXPORT(name, type, desc)
+
+#define MSH_CMD_EXPORT(command, desc)
+#elif !defined(FINSH_USING_SYMTAB)
+#define FINSH_FUNCTION_EXPORT_CMD(name, cmd, desc)
 #endif
 
 /* event length */