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/mtdchar.c b/drivers/mtd/mtdchar.c
index c51f04a..c7f4846 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -232,7 +232,7 @@
 			break;
 		}
 		default:
-			ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
+			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 		}
 		/* Nand returns -EBADMSG on ECC errors, but it returns
 		 * the data. For our userspace tools it is important