The buttons of the Wii Remote Nunchuck extension are actually active low.
Fix the parser to forward the inverted values. The comment in the function
always said "0 == pressed" but the implementation was wrong from the
beginning.

Cc: stable@vger.kernel.org
Reported-by: Victor Quicksilver <victor.quicksilver@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>