mtd: nand_bbt: refactor check_pattern_no_oob()
This function only returns 0 or -1, so make that clear.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>