staging: unisys: visorbus: refactor setup_crash_devices_work_queue

The if statement was sending us down the happy path with the error path
in the else. This can be simplified by having the if be the error and
just falling through with the good path.

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>