vmbus: make sysfs names consistent with PCI

In commit 9a56e5d6a0ba ("Drivers: hv: make VMBus bus ids persistent")
the name of vmbus devices in sysfs changed to be (in 4.9-rc1):
  /sys/bus/vmbus/vmbus-6aebe374-9ba0-11e6-933c-00259086b36b

The prefix ("vmbus-") is redundant and differs from how PCI is
represented in sysfs. Therefore simplify to:
  /sys/bus/vmbus/6aebe374-9ba0-11e6-933c-00259086b36b

Please merge this before 4.9 is released and the old format
has to live forever.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/vmbus_drv.c

@@ -961,7 +961,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 {
 	int ret = 0;
 
-	dev_set_name(&child_device_obj->device, "vmbus-%pUl",
+	dev_set_name(&child_device_obj->device, "%pUl",
 		     child_device_obj->channel->offermsg.offer.if_instance.b);
 
 	child_device_obj->device.bus = &hv_bus;