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/rfd_ftl.c b/drivers/mtd/rfd_ftl.c
index 39de872..d9fe2d0 100644
--- a/drivers/mtd/rfd_ftl.c
+++ b/drivers/mtd/rfd_ftl.c
@@ -200,9 +200,9 @@
 		part->sector_map[i] = -1;
 
 	for (i=0, blocks_found=0; i<part->total_blocks; i++) {
-		rc = part->mbd.mtd->read(part->mbd.mtd,
-				i * part->block_size, part->header_size,
-				&retlen, (u_char*)part->header_cache);
+		rc = mtd_read(part->mbd.mtd, i * part->block_size,
+			      part->header_size, &retlen,
+			      (u_char *)part->header_cache);
 
 		if (!rc && retlen != part->header_size)
 			rc = -EIO;
@@ -250,8 +250,8 @@
 
 	addr = part->sector_map[sector];
 	if (addr != -1) {
-		rc = part->mbd.mtd->read(part->mbd.mtd, addr, SECTOR_SIZE,
-						&retlen, (u_char*)buf);
+		rc = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
+			      (u_char *)buf);
 		if (!rc && retlen != SECTOR_SIZE)
 			rc = -EIO;
 
@@ -372,9 +372,8 @@
 	if (!map)
 		goto err2;
 
-	rc = part->mbd.mtd->read(part->mbd.mtd,
-		part->blocks[block_no].offset, part->header_size,
-		&retlen, (u_char*)map);
+	rc = mtd_read(part->mbd.mtd, part->blocks[block_no].offset,
+		      part->header_size, &retlen, (u_char *)map);
 
 	if (!rc && retlen != part->header_size)
 		rc = -EIO;
@@ -413,8 +412,8 @@
 			}
 			continue;
 		}
-		rc = part->mbd.mtd->read(part->mbd.mtd, addr,
-			SECTOR_SIZE, &retlen, sector_data);
+		rc = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
+			      sector_data);
 
 		if (!rc && retlen != SECTOR_SIZE)
 			rc = -EIO;
@@ -563,8 +562,9 @@
 		}
 	}
 
-	rc = part->mbd.mtd->read(part->mbd.mtd, part->blocks[block].offset,
-		part->header_size, &retlen, (u_char*)part->header_cache);
+	rc = mtd_read(part->mbd.mtd, part->blocks[block].offset,
+		      part->header_size, &retlen,
+		      (u_char *)part->header_cache);
 
 	if (!rc && retlen != part->header_size)
 		rc = -EIO;