staging: unisys: fix CamelCased diagpool bus/dev names

Fix CamelCase names:

g_diagpoolBusNo => g_diagpool_bus_no
g_diagpoolDevNo => g_diagpool_dev_no

Update all references to the changed names.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>