sandbox: cros_ec: exynos: Drop use of cros_ec_get_error()

This function is really just a call to uclass_get_device() and there is no
reason why the caller cannot do it. Update sandbox and snow accordingly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Minkyu Kang <mk7.kang@samsung.com>

common/cros_ec.c

@@ -25,15 +25,3 @@ struct udevice *board_get_cros_ec_dev(void)
 	}
 	return dev;
 }
-
-int cros_ec_get_error(void)
-{
-	struct udevice *dev;
-	int ret;
-
-	ret = uclass_get_device(UCLASS_CROS_EC, 0, &dev);
-	if (ret && ret != -ENODEV)
-		return ret;
-
-	return 0;
-}