Run(): rename 'copyStdio' to 'copyPipes'
Run(): rename 'copyStdio' to 'copyPipes'

Rename a variable.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

Closes: #795
Approved by: rhatdan

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