HID:hid-lg4ff: Scale autocentering force properly on Logitech wheel

commit f8c231569a7a455dfa1907294a46ba52b3aa8859 upstream.

Adjust the scaling and lineartity to match that of the Windows
driver (from MOMO testing).

Reported-by: Elias Vanderstuyft <elias.vds@gmail.com>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>