Fix a small memleak in delv

(cherry picked from commit d00b3f47)
20 jobs for 712-memleak-in-delv-v9_12 in 15 minutes and 51 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #101818
amd64 docker linux

00:00:20

 
  Build
passed build:centos:centos6:amd64 #101819
amd64 docker linux

00:02:51

passed build:centos:centos7:amd64 #101820
amd64 docker linux

00:03:24

passed build:debian:sid:amd64 #101821
linux amd64 docker

00:02:35

passed build:debian:sid:i386 #102862
linux docker i386

00:01:43

passed noassert:build:debian:sid:amd64 #101823
amd64 docker linux

00:02:35

passed build:debian:sid:i386 #101822
i386 docker linux

00:03:23

 
  Test
passed docs:debian:sid:amd64 #101824
amd64 docker linux

00:00:54

passed install:debian:sid:amd64 #101833
amd64 docker linux

00:02:04

passed noassert:systemtest:debian:sid:amd64 #101835
amd64 docker linux

00:04:59

passed noassert:unittest:debian:sid:amd64 #101834
amd64 docker linux

00:00:50

passed systemtest:centos:centos6:amd64 #101829
amd64 docker linux

00:04:55

passed systemtest:centos:centos7:amd64 #101830
amd64 docker linux

00:04:54

passed systemtest:debian:sid:amd64 #101831
amd64 docker linux

00:04:59

passed systemtest:debian:sid:i386 #102863
linux docker i386

00:05:01

passed unittest:centos:centos6:amd64 #101825
amd64 docker linux

00:00:54

passed unittest:centos:centos7:amd64 #101826
amd64 docker linux

00:00:54

passed unittest:debian:sid:amd64 #101827
amd64 docker linux

00:00:50

passed unittest:debian:sid:i386 #101828
i386 docker linux

00:00:45

failed systemtest:debian:sid:i386 #101832
i386 docker linux

00:05:32