staging: unisys: fix CamelCase local toolAction

Rename the CamelCase local

toolAction => tool_action

In both of the sysfs functions for exposing this value, and update all
references to use the corrected name.

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