staging: unisys: visorbus: remove noisy postcode from visorchipset_exit

The postcodes in visorchipset_exit were not displaying errors, they can
just be removed.

Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>