mtd: nand: gpio: 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 <yamada.masahiro@socionext.com>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
index 6317f68..0d24857 100644
--- a/drivers/mtd/nand/gpio.c
+++ b/drivers/mtd/nand/gpio.c
@@ -286,10 +286,9 @@
 	if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
 		gpio_direction_output(gpiomtd->plat.gpio_nwp, 1);
 
-	if (nand_scan(mtd, 1)) {
-		ret = -ENXIO;
+	ret = nand_scan(mtd, 1);
+	if (ret)
 		goto err_wp;
-	}
 
 	if (gpiomtd->plat.adjust_parts)
 		gpiomtd->plat.adjust_parts(&gpiomtd->plat, mtd->size);