chroot: fix the args check
chroot: fix the args check

two arguments are required by the program

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1076
Approved by: rhatdan

rhatdan/buildah,projectatomic/buildah,rhatdan/buildah,nalind/buildah-1,rhatdan/buildah,TomSweeneyRedHat/buildah,ipbabble/buildah,ipbabble/buildah,nalind/buildah-1,nalind/buildah-1,projectatomic/buildah,projectatomic/buildah,TomSweeneyRedHat/buildah,nalind/buildah,TomSweeneyRedHat/buildah,nalind/buildah