Staging: unisys: Remove isServer arg from init_vbus_channel()

The init_vbus_channel() function is never called with the isServer
argument equal to TRUE, so just get rid of the argument altogether.
This also means that the code in the function that would be executed
in the server case can be removed since it is never executed.

Signed-off-by: Ken Cox <jkc@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>