[MTD] [OneNAND] Exit loop only when column start with 0

The JFFS2 requests OOB function from column 0.
But the oobtest in nand-tests doesn't.
So we only exit loop only when column start with 0.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>