hv: make vmbus_loglevel writeable

make /sys/module/hv_vmbus/parameters/vmbus_loglevel writeable by root.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/vmbus_drv.c

@@ -827,7 +827,7 @@ static void __exit hv_pci_exit(void)
 
 MODULE_LICENSE("GPL");
 MODULE_VERSION(HV_DRV_VERSION);
-module_param(vmbus_loglevel, int, S_IRUGO);
+module_param(vmbus_loglevel, int, S_IRUGO|S_IWUSR);
 
 module_init(hv_pci_init);
 module_exit(hv_pci_exit);