fat.c: fix printf() length modifier

fat.c: fix printf() length modifier

The DIRENTSPERBLOCK utilizes sizeof() which will return a size_t which has no
fixed size. Therefor use correct length modifer for printf() statement to
prevent compiler warnings.

This patch fixes following warning:

---8<---
fat.c: In function 'do_fat_read':
fat.c:879: warning: format '%d' expects type 'int', but argument 4 has type 'long unsigned int'
--->8---

Signed-off-by: Andreas Bießmann <[email protected]>
cc: Mike Frysinger <[email protected]>
cc: Thomas Chou <[email protected]>
cc: [email protected]
cc: [email protected]
Acked-by: Mike Frysinger <[email protected]>