Fix memory leak in lex_test.c

(cherry picked from commit 7a3eb391)
18 jobs for 711-fix-memory-leak-in-lex_test-v9_11 in 7 minutes and 11 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #101645
linux amd64 docker

00:00:18

 
  Build
passed build:centos:centos6:amd64 #101646
amd64 docker linux

00:02:17

passed build:centos:centos7:amd64 #101647
amd64 docker linux

00:02:28

passed build:debian:sid:amd64 #101648
amd64 docker linux

00:01:41

passed build:debian:sid:i386 #101649
i386 docker linux

00:01:26

passed noassert:build:debian:sid:amd64 #101650
amd64 docker linux

00:01:27

 
  Test
passed docs:debian:sid:amd64 #101651
amd64 docker linux

00:00:56

passed install:debian:sid:amd64 #101660
amd64 docker linux

00:01:34

passed noassert:systemtest:debian:sid:amd64 #101662
amd64 docker linux

00:04:12

passed noassert:unittest:debian:sid:amd64 #101661
amd64 docker linux

00:01:05

passed systemtest:centos:centos6:amd64 #101656
amd64 docker linux

00:04:14

passed systemtest:centos:centos7:amd64 #101657
amd64 docker linux

00:04:19

passed systemtest:debian:sid:amd64 #101658
amd64 docker linux

00:04:02

passed systemtest:debian:sid:i386 #101659
i386 docker linux

00:04:22

passed unittest:centos:centos6:amd64 #101652
amd64 docker linux

00:00:55

passed unittest:centos:centos7:amd64 #101653
amd64 docker linux

00:01:08

passed unittest:debian:sid:amd64 #101654
amd64 docker linux

00:00:50

passed unittest:debian:sid:i386 #101655
i386 docker linux

00:00:55