[title]
Check for an excessive number of unused I/O devices

[description]
Even when they are unused (offline), I/O devices consume memory and CPU time
both during the boot process and when I/O configuration changes occur on a
running system. In particular, when new I/O devices or I/O paths become
available or when existing I/O devices or I/O paths become unavailable,
resources are wasted to unused I/O devices.

This check uses the "lscss" command to identify unused I/O devices.

[param ratio_limit]
Threshold for the percentage of unused (offline) I/O devices. If this threshold
is exceeded, an exception is issued.
Valid values are integers in the range 1 to 100.

[param device_print_limit]
Threshold for the absolute number of unused (offline) I/O devices. If the
number of unused I/O devices exceeds this threshold, an exception is issued.
Valid values are positive integers.
