Do not attempt to load the firmware a second time. If you reboot your

Do not attempt to load the firmware a second time. If you reboot your
machine but leave your KLSI adapter plugged into your USB port, it
may stay powered on and retain its firmware in memory. Trying to load
the firmware again in this case will wedge the chip. Try to detect this
in the kue_load_fw() routine and bail if the firmware is already
loaded and running.

Also, in the probe/match routine, force the revision code to the
hardware default and force a rescan of the quirk database. This is
necessary because the adapter will return a different revision code
if the firmware has been loaded. Without the firmware, the revision
code is 0x002. With the firmware, the revision code is 0x202. This
confuses the quirk mechanism, which won't match a quirk to a device
unless the revision code agrees with the quirk table entry.

This makes probe/attach of these devices somewhat more reliable.

Also add a few comments about the device's operation.