Drivers: hv: Fix the bug in generating the guest ID

Fix the bug in the generation of the guest ID. Without this fix
the host side telemetry code is broken.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Fixes: 352c9624

 ("Drivers: hv: vmbus: Move the definition of generate_guest_id()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>