Fix root directory of the mountpoint being owned by real root. This is
unique to ZFS because of the way file mountpoints are created using the
ZFS tooling, and the remapping that happens at layer unpack doesn't
impact this root (already created) holding directory for the layer.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Upstream-commit: aef0995b02a5a90ad74e6d91901d7bc8a9713796
Component: engine