staging: unisys: visorbus: replaced use of vague 'x' variable

In client_bus_info_show, the variable 'x' is used to create keep track
of the offset that the current 'pos' in the output buffer needs to be
incremented by. Since 'off' is already taken 'shift' was used since it's
used to shift the pointer.

Signed-off-by: Alexander Curtin <alexander.curtin@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>