mtd: ecc_strength is at ecc step granularity

ecc_strength element of mtd_info will be the strength of one ecc step, not of
the entire writesize, as was previously planned.  This is the appropriate way
because, as was pointed out¹, bit errors in excess of the strength of one
step can cause a hard error if they all occur within the same ecc region.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040313.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index cf5ea8c..cd0119d 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -164,7 +164,7 @@
 	/* ECC layout structure pointer - read only! */
 	struct nand_ecclayout *ecclayout;
 
-	/* max number of correctible bit errors per writesize */
+	/* max number of correctible bit errors per ecc step */
 	unsigned int ecc_strength;
 
 	/* Data for variable erase regions. If numeraseregions is zero,