powernv: Fix permissions on sysparam sysfs entries

Everyone can write to these files, which is not what we want.

Cc: stable@vger.kernel.org # 3.15
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/powernv/opal-sysparam.c

@@ -260,10 +260,10 @@ void __init opal_sys_param_init(void)
 			attr[i].kobj_attr.attr.mode = S_IRUGO;
 			break;
 		case OPAL_SYSPARAM_WRITE:
-			attr[i].kobj_attr.attr.mode = S_IWUGO;
+			attr[i].kobj_attr.attr.mode = S_IWUSR;
 			break;
 		case OPAL_SYSPARAM_RW:
-			attr[i].kobj_attr.attr.mode = S_IRUGO | S_IWUGO;
+			attr[i].kobj_attr.attr.mode = S_IRUGO | S_IWUSR;
 			break;
 		default:
 			break;