mtd: cafe_nand: fix an & vs | mistake

The intent here was clearly to set result to true if the 0x40000000 flag
was set.  But instead there was a | vs & typo and we always set result
to true.

Artem: check the spec at
wiki.laptop.org/images/5/5c/88ALP01_Datasheet_July_2007.pdf
and this fix looks correct.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>