Fix ownership of non-existing parent dir

During "COPY" or other tar unpack operations, a target/destination
parent dir might not exist and should be created with ownership of the
root in the right context (including remapped root when user namespaces
are enabled)

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)