HID: LG4FF: Remove unnecessary deadzone code

This patch removes code which is now unnecessary for setting the fuzz/flat
characterics for the logitech DFP wheel. This is now done in the previous
patch by marking the wheel as a multi-axis device.

Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>