staging: unisys: visornic: simplify visornic if statements

Changes the conditional logic by looking for the absence of work
to do, instead of the opposite.

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