touchpad: drop check for left button areas

No functional changes, anything that's in the top/bottom area but not in the
respective middle/right area is a left button.

Introduced by 13bda5ad

Fixes coverity complaint about use of uninitialized variable.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
42 jobs for master in 6 minutes and 23 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Docker Check
passed arch:rolling@docker-check #18059

00:00:19

passed arch:rolling@docker-clean #18065

00:00:28

passed fedora:27@docker-check #18056

00:00:20

passed fedora:27@docker-clean #18062

00:00:31

passed fedora:28@docker-check #18055

00:00:20

passed fedora:28@docker-clean #18061

00:00:31

passed freebsd:11.2@docker-check #18060

00:00:19

passed freebsd:11.2@docker-clean #18066

00:00:29

passed ubuntu:17.10@docker-check #18057

00:00:19

passed ubuntu:17.10@docker-clean #18063

00:00:28

passed ubuntu:18.04@docker-check #18058

00:00:20

passed ubuntu:18.04@docker-clean #18064

00:00:29

 
  Docker Prep
passed arch:rolling@docker-prep #18071

00:00:19

manual arch:rolling@force-docker-prep #18077
allowed to fail manual
passed fedora:27@docker-prep #18068

00:00:20

manual fedora:27@force-docker-prep #18074
allowed to fail manual
passed fedora:28@docker-prep #18067

00:00:20

manual fedora:28@force-docker-prep #18073
allowed to fail manual
passed freebsd:11.2@docker-prep #18072

00:00:18

manual freebsd:11.2@force-docker-prep #18078
allowed to fail manual
passed ubuntu:17.10@docker-prep #18069

00:00:21

manual ubuntu:17.10@force-docker-prep #18075
allowed to fail manual
passed ubuntu:18.04@docker-prep #18070

00:00:21

manual ubuntu:18.04@force-docker-prep #18076
allowed to fail manual
 
  Build
passed arch:rolling@default-build #18094

00:00:39

passed fedora:27@default-build #18079

00:00:53

passed fedora:28@build-no-debuggui #18087

00:00:59

passed fedora:28@build-no-debuggui-nodeps #18088

00:01:00

passed fedora:28@build-no-docs #18085

00:00:37

passed fedora:28@build-no-docs-nodeps #18086

00:00:52

passed fedora:28@build-no-libwacom #18083

00:00:45

passed fedora:28@build-no-libwacom-nodeps #18084

00:00:54

passed fedora:28@build-no-tests #18089

00:00:37

passed fedora:28@build-no-tests-nodeps #18090

00:00:37

passed fedora:28@default-build #18080

00:00:51

passed fedora:28@default-build-release #18081

00:00:54

passed fedora:28@scan-build #18082

00:03:11

passed fedora:28@valgrind #18091

00:00:42

passed freebsd:11.2@default-build #18095

00:00:24

passed ubuntu:17.10@default-build #18092

00:00:42

passed ubuntu:18.04@default-build #18093

00:00:41

 
  Deploy
passed wayland-web #18096

00:00:16