Fixing this error:
atmel_nand.c:718:20: warning: Using plain integer as NULL pointer
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NArtem Bityutskiy <dedekind1@gmail.com>