staging: unisys: visorbus: Remove two passthrough postcode macros

Remove two passthrough macros that are only called from a single
location and make the resultant vmcall directly.

Signed-off-by: Bryan Thompson <bryan.thompson@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>