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/fs/logfs/dev_mtd.c b/fs/logfs/dev_mtd.c
index 0463628..3ee6435 100644
--- a/fs/logfs/dev_mtd.c
+++ b/fs/logfs/dev_mtd.c
@@ -20,7 +20,7 @@
 	size_t retlen;
 	int ret;
 
-	ret = mtd->read(mtd, ofs, len, &retlen, buf);
+	ret = mtd_read(mtd, ofs, len, &retlen, buf);
 	BUG_ON(ret == -EINVAL);
 	if (ret)
 		return ret;