Drivers: hv: vmbus: fix the building warning with hyperv-keyboard

With the recent change af3ff643
(Drivers: hv: vmbus: Use uuid_le type consistently), we always get this
warning:

  CC [M]  drivers/input/serio/hyperv-keyboard.o
drivers/input/serio/hyperv-keyboard.c:427:2: warning: missing braces around
	initializer [-Wmissing-braces]
  { HV_KBD_GUID, },
  ^
drivers/input/serio/hyperv-keyboard.c:427:2: warning: (near initialization
	for .id_table[0].guid.b.) [-Wmissing-braces]

The patch fixes the warning.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>