[BSP] fix the compiling error
-#include <rtthread.h>
-#include <dfs.h>
-
#include <stdio.h>
#include <string.h>
-#ifdef _WIN32
#include <stdlib.h>
-#endif
+
+#include <rtthread.h>
+#include <dfs.h>
#ifdef DEBUG
# define SD_TRACE rt_kprintf
