mtd: introduce mtd_write interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
index b0644d2..ac7f1f1 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -102,7 +102,7 @@
 	 * Next, write the data to flash.
 	 */
 
-	ret = mtd->write(mtd, pos, len, &retlen, buf);
+	ret = mtd_write(mtd, pos, len, &retlen, buf);
 	if (ret)
 		return ret;
 	if (retlen != len)
@@ -152,7 +152,7 @@
 		mtd->name, pos, len);
 
 	if (!sect_size)
-		return mtd->write(mtd, pos, len, &retlen, buf);
+		return mtd_write(mtd, pos, len, &retlen, buf);
 
 	while (len > 0) {
 		unsigned long sect_start = (pos/sect_size)*sect_size;