[PATCH] s390: minor fix in cu3088

In case of a parse error for the cu3088 group attribute,
return -EINVAL instead of count.
Signed-off-by: NFrank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/s390/net/cu3088.c

@@ -77,7 +77,7 @@ group_write(struct device_driver *drv, const char *buf, size_t count)
 		int len;
 
 		if (!(end = strchr(start, delim[i])))
-			return count;
+			return -EINVAL;
 		len = min_t(ptrdiff_t, BUS_ID_SIZE, end - start + 1);
 		strlcpy (bus_ids[i], start, len);
 		argv[i] = bus_ids[i];