stat: fix test on travis
stat: fix test on travis

/dev/pts/ptmx seems to be the only character special file in /dev
which is not a bind-mount in the docker container run by travis.
gnu stat does not detect these mounts, so produces a different
output for /dev/zero.

Arcterus/coreutils,uutils/coreutils,keunwoo/coreutils,uutils/coreutils,keunwoo/coreutils,tempbottle/coreutils,tempbottle/coreutils,Arcterus/coreutils,uutils/coreutils