hwmon: (atxp1) Set and use error code from vid_to_reg()

vid_to_reg() returns -1 if it encounters an error. Return -EINVAL instead.
Its only caller, atxp1_storevcore(), doesn't use the return code but
returns -1 instead, which is wrong anyway as it means -EPERM.
Use the return value from vid_to_reg() instead to report the error.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/atxp1.c b/drivers/hwmon/atxp1.c
index aecb9ea..ddff02e 100644
--- a/drivers/hwmon/atxp1.c
+++ b/drivers/hwmon/atxp1.c
@@ -147,10 +147,9 @@
 
 	/* Calculate VID */
 	vid = vid_to_reg(vcore, data->vrm);
-
 	if (vid < 0) {
 		dev_err(dev, "VID calculation failed.\n");
-		return -1;
+		return vid;
 	}
 
 	/*