drivers/mtd/nand: sparse fixes

nand_ecc.c:82:5: warning: symbol 'nand_calculate_ecc' was not declared. Should it be static?
nand_ecc.c:155:5: warning: symbol 'nand_correct_data' was not declared. Should it be static?
nand_base.c:2854:1: error: directive in argument list
nand_base.c:2856:1: error: directive in argument list

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Acked-by: Scott Wood <scottwood@freescale.com>