pkg/chrootarchive: TestChrootTarUntar fix copy/paste mistake
pkg/chrootarchive: TestChrootTarUntar fix copy/paste mistake

Introduced in 3ac6394b8082d4700483d52fbfe54914be537d9e, which makes no mention
of a reason for extracting to the same directory as we created the archive from,
so I assume this was a copy/paste mistake and the path was meant to be "dest",
not "src".

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

thaJeztah/docker,Ramzec/docker,mahak/docker,jimjag/docker,trebonian/docker,mahak/docker,jimjag/docker,Mokolea/docker,moby/moby,Ramzec/docker,moby/moby,Ramzec/docker,konstruktoid/docker-upstream,thaJeztah/docker,trebonian/docker,konstruktoid/docker-upstream,trebonian/docker,mahak/docker,Mokolea/docker,moby/moby,thaJeztah/docker,jimjag/docker,thaJeztah/docker,jimjag/docker,mahak/docker,konstruktoid/docker-upstream,Mokolea/docker,konstruktoid/docker-upstream,Mokolea/docker,trebonian/docker,moby/moby,Ramzec/docker