drivers: hv: Don't OOPS when you cannot init vmbus

drivers: hv: Don't OOPS when you cannot init vmbus

commit cf6a2eacbcb2593b5b91d0817915c4f0464bb534 upstream.

The hv vmbus driver was causing an OOPS since it was trying to register drivers
on top of the bus even if initialization of the bus has failed for some
reason (such as the odd chance someone would run a hv enabled kernel in a
non-hv environment).

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>