mtd: nand: cmx270: return error code of nand_scan() on error

The nand_scan() returns an appropriate error value when it fails.
Use it instead of the fixed error code -ENXIO.

Signed-off-by: Masahiro Yamada <[e-mail]>
Reviewed-by: Marek Vasut <[e-mail]>
Signed-off-by: Boris Brezillon <[e-mail]>

drivers/mtd/nand/cmx270_nand.c

···
 	this->write_buf = cmx270_write_buf;
 
 	/* Scan to find existence of the device */
-	if (nand_scan (cmx270_nand_mtd, 1)) {
+	ret = nand_scan(cmx270_nand_mtd, 1);
+	if (ret) {
 		pr_notice("No NAND device\n");
-		ret = -ENXIO;
 		goto err_scan;
 	}