mtd: introduce mtd_read 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/ssfdc.c b/drivers/mtd/ssfdc.c
index 976e3d2..293e22a 100644
--- a/drivers/mtd/ssfdc.c
+++ b/drivers/mtd/ssfdc.c
@@ -123,8 +123,8 @@
 	 */
 	for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) {
 		if (!mtd->block_isbad(mtd, offset)) {
-			ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen,
-				sect_buf);
+			ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen,
+				       sect_buf);
 
 			/* CIS pattern match on the sector buffer */
 			if (ret < 0 || retlen != SECTOR_SIZE) {
@@ -156,7 +156,7 @@
 	size_t retlen;
 	loff_t offset = (loff_t)sect_no << SECTOR_SHIFT;
 
-	ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
+	ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
 	if (ret < 0 || retlen != SECTOR_SIZE)
 		return -1;