Has the 'wacom_notify_battery' function take on the job of detecting if
updating the power supply is necessary to remove multiple
nearly-identical 'if' blocks.
Signed-off-by: NJason Gerecke <killertofu@gmail.com>
Acked-by: NPing Cheng <pingc@wacom.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>