fix casecompare return type for ninfo, tkey, txt

10 jobs for 343-casecompare-of-ninfo-tkey-txt-have-wrong-return-type in 8 minutes and 12 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Precheck
passed #19782
amd64 docker linux
precheck:debian:sid:amd64

00:00:11

 
  Build
passed #19783
amd64 docker linux
build:clang:debian:sid:amd64

00:03:01

passed #19785
i386 docker linux
build:clang:debian:sid:i386

00:03:19

passed #19784
amd64 docker linux
build:debian:sid:amd64

00:01:54

passed #19786
i386 docker linux
build:debian:sid:i386

00:01:58

 
  Test
passed #19790
amd64 docker linux
systemtest:debian:sid:amd64

00:04:39

passed #19791
i386 docker linux
systemtest:debian:sid:i386

00:04:39

passed #19788
amd64 docker linux
unittest:clang:debian:sid:amd64

00:00:46

passed #19787
amd64 docker linux
unittest:debian:sid:amd64

00:00:44

passed #19789
i386 docker linux
unittest:debian:sid:i386

00:00:45