Input: appletouch - miscellaneous code cleanups

This patch does some code cleanups in appletouch:
 * useless comment removal
 * make almost checkpatch clean
 * make sparse clean

Signed-off-by: Sven Anders <anders@anduras.de>
[jberg: most of the changes including removing much of the original patch]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>