Fix computation in nand_util.c:get_len_incl_bad

Depending on offset, flash size and the number of bad blocks,
get_len_incl_bad may return a too small value which may lead to:

1) If there are no bad blocks, nand_{read,write}_skip_bad chooses the
bad block aware read/write code. This may hurt performance, but does
not have any adverse effects.

2) If there are bad blocks, the nand_{read,write}_skip_bad may choose
the bad block unaware read/write code (if len_incl_bad == *length)
which leads to corrupted data.

Signed-off-by: Daniel Hobi <daniel.hobi@schmid-telecom.ch>

drivers/mtd/nand/nand_util.c

@@ -452,7 +452,7 @@ static size_t get_len_incl_bad (nand_info_t *nand, loff_t offset,
 		len_incl_bad += block_len;
 		offset       += block_len;
 
-		if ((offset + len_incl_bad) >= nand->size)
+		if (offset >= nand->size)
 			break;
 	}