kernel: mtdsplit_uimage: use -ENOENT instead of -ENODEV

New linux version will check the return code of parser on subpartitions.
The only valid case for skipping a parser with an error is -ENOENT.

Change the relevant entry to -ENOENT.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_uimage.c

@@ -217,6 +217,7 @@ static int __mtdsplit_parse_uimage(struct mtd_info *master,
 		if (ret) {
 			pr_debug("no rootfs before uImage in \"%s\"\n",
 				 master->name);
+			ret = -ENOENT;
 			goto err_free_buf;
 		}