mtd: introduce mtd_read_user_prot_reg 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 002a8b5..6aa3fb4 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -217,7 +217,8 @@
 						     &retlen, kbuf);
 			break;
 		case MTD_FILE_MODE_OTP_USER:
-			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
+			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
+						     &retlen, kbuf);
 			break;
 		case MTD_FILE_MODE_RAW:
 		{