staging: mt29f_spinand: Enable the read ECC before program the page

Current program_page function did following operation:

1. read page (with ECC OFF)
2. modify the page
3. write the page (with ECC ON)

For some case(buggy flash Chip), while read the page without ECC ON,
we may read the page with bit flip error and modify that bad page without
knowing the bit flip error on that page.
also we re-calculate the hash for bad page and write it.
This could bring potential in-consistency problem with Flash data.

Verify this logic with GIGA DEVICE Part(GD5F2GQ4RCFIG):
we see this in-conststency problem wit Giga Device and fix on
this patch resovle that issue.
Signed-off-by: Arun Nagendran <arunrasppi@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/staging/mt29f_spinand/mt29f_spinand.c

@@ -496,8 +496,12 @@ static int spinand_program_page(struct spi_device *spi_nand,
 	if (!wbuf)
 		return -ENOMEM;
 
-	enable_read_hw_ecc = 0;
-	spinand_read_page(spi_nand, page_id, 0, CACHE_BUF, wbuf);
+	enable_read_hw_ecc = 1;
+	retval = spinand_read_page(spi_nand, page_id, 0, CACHE_BUF, wbuf);
+	if (retval < 0) {
+		dev_err(&spi_nand->dev, "ecc error on read page!!!\n");
+		return retval;
+	}
 
 	for (i = offset, j = 0; i < len; i++, j++)
 		wbuf[i] &= buf[j];