Description for hdev, work and battery_timer of struct magicmouse_sc were
missing. Fix that.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312261056.AmFPDIL5-lkp@intel.com/Signed-off-by: Jiri Kosina <jkosina@suse.com>