drivers/scsi/pm8001/pm8001_ctl.c: avoid world-writable sysfs files.

In line with practice for module parameters, we're adding a build-time
check that sysfs files aren't world-writable.

Cc: Lindar Liu <lindar_liu@usish.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/scsi/pm8001/pm8001_ctl.c

@@ -729,7 +729,7 @@ static ssize_t pm8001_show_update_fw(struct device *cdev,
 			flash_error_table[i].reason);
 }
 
-static DEVICE_ATTR(update_fw, S_IRUGO|S_IWUGO,
+static DEVICE_ATTR(update_fw, S_IRUGO|S_IWUSR|S_IWGRP,
 	pm8001_show_update_fw, pm8001_store_update_fw);
 struct device_attribute *pm8001_host_attrs[] = {
 	&dev_attr_interface_rev,