create relationsip for LOS_MAX_DIR_NAME_LEN and FF_LFN_BUF
#define FF_USE_LFN 2
-#define FF_MAX_LFN 255
+#define FF_MAX_LFN LOS_MAX_DIR_NAME_LEN
/* The FF_USE_LFN switches the support for LFN (long file name).
/
/ 0: Disable LFN. FF_MAX_LFN has no effect.
