mtd: mtdoops: skip reading initially bad blocks

Use block_isbad to check and skip the bad blocks reading.
This will allow to get rid of the read errors if bad blocks
are present initially.

Cc: stable@kernel.org
Signed-off-by: NRoman Tereshonkov <roman.tereshonkov@nokia.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdoops.c

@@ -253,6 +253,9 @@ static void find_next_position(struct mtdoops_context *cxt)
 	size_t retlen;
 
 	for (page = 0; page < cxt->oops_pages; page++) {
+		if (mtd->block_isbad &&
+		    mtd->block_isbad(mtd, page * record_size))
+			continue;
 		/* Assume the page is used */
 		mark_page_used(cxt, page);
 		ret = mtd->read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,