remove RT_USING_LIBC from dfs_fs.h

components/dfs/include/dfs_fs.h

@@ -12,10 +12,9 @@
 #define __DFS_FS_H__
 
 #include <dfs.h>
-#ifdef RT_USING_LIBC
 #include <sys/types.h>
-#endif
 #include <sys/errno.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif