This was another merge problem that wasn't a data conflict, but due to
independent changes in two branches that just didn't work together.
The pcc-acpi staging driver used
acpi_driver_data(device) = hotkey;
to set driver data, but the ACPI merge made that invalid in commit
db89b4f0db ("ACPI: catch calls of
acpi_driver_data on pointer of wrong type"), and now you're supposed to
just do.
device->driver_data = hotkey;
instead.
Fix it up.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>