staging: unisys: visorbus: initialize variables

Initializes previously uninitialized variables that were flagged
as being problematic by Smatch.

Signed-off-by: David Binder <david.binder@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>