silence "unused return value" warning

30 jobs for silence-compiler-warning in 22 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #95941
amd64 docker linux

00:00:17

 
  Build
canceled build:centos:centos6:amd64 #95942
amd64 docker linux

00:00:03

canceled build:centos:centos7:amd64 #95943
amd64 docker linux

00:00:03

canceled build:clang:debian:stretch:amd64 #95944
amd64 docker linux

00:00:03

canceled build:clang:debian:stretch:i386 #95948
i386 docker linux

00:00:02

canceled build:debian:jessie:amd64 #95945
amd64 docker linux

00:00:03

canceled build:debian:sid:amd64 #95947
amd64 docker linux

00:00:03

canceled build:debian:sid:i386 #95949
i386 docker linux

00:00:02

canceled build:debian:stretch:amd64 #95946
amd64 docker linux

00:00:03

canceled noassert:build:debian:sid:amd64 #95951
amd64 docker linux

00:00:02

canceled pkcs11:build:debian:sid:amd64 #95950
amd64 docker linux

00:00:02

 
  Test
canceled docs:debian:sid:amd64 #95952
amd64 docker linux

canceled install:debian:sid:amd64 #95966
amd64 docker linux

canceled noassert:systemtest:debian:sid:amd64 #95970
amd64 docker linux

canceled noassert:unittest:debian:sid:amd64 #95969
amd64 docker linux

canceled pkcs11:systemtest:debian:sid:amd64 #95968
amd64 docker linux

canceled pkcs11:unittest:debian:sid:amd64 #95967
amd64 docker linux

canceled systemtest:centos:centos6:amd64 #95960
amd64 docker linux

canceled systemtest:centos:centos7:amd64 #95961
amd64 docker linux

canceled systemtest:debian:jessie:amd64 #95962
linux amd64 docker

canceled systemtest:debian:sid:amd64 #95964
amd64 docker linux

canceled systemtest:debian:sid:i386 #95965
i386 docker linux

canceled systemtest:debian:stretch:amd64 #95963
amd64 docker linux

canceled unittest:centos:centos6:amd64 #95953
amd64 docker linux

canceled unittest:centos:centos7:amd64 #95954
amd64 docker linux

canceled unittest:clang:debian:stretch:amd64 #95958
amd64 docker linux

canceled unittest:debian:jessie:amd64 #95955
amd64 docker linux

canceled unittest:debian:sid:amd64 #95957
amd64 docker linux

canceled unittest:debian:sid:i386 #95959
i386 docker linux

canceled unittest:debian:stretch:amd64 #95956
amd64 docker linux