UBIFS: fix printk format warnings

fs/ubifs/dir.c:428: warning: format '%llu' expects type 'long long
unsigned int', but argument 5 has type 'long unsigned int'

fs/ubifs/debug.c:541: warning: format '%llu' expects type 'long long
unsigned int', but argument 2 has type 'long unsigned int'

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>