VSOCK: Fix init order

This fixes the order of initialization in preparation for splitting the module.
The next part will actually split them out, so we still call reg/unreg
directly.

Signed-off-by: Andy King <acking@vmware.com>
VSOCK: Fix oops in destruct

DGRAM sockets don't have notify ops, but we don't check that in destruct.  Fix
it so that we test before calling.  Also, free the transport.

Signed-off-by: Andy King <acking@vmware.com>