Treat dest as normal file when copying out of podman containers

Implement container_cp() function for podman to be more in line with
"docker cp" where DEST is treated as a normal file.

The lack of -T option caused the container logs to be copied twice,
once in containers/<name>/log and a second time in
containers/<name>/log/log.

Change-Id: Ia6e20e29f8fe55330538f46b2b91d09f0129f43f

roles/collect-logs/tasks/collect.yml

@@ -242,7 +242,7 @@
                 # See also: https://github.com/containers/libpod/issues/613
                 container_cp() {
                   mnt=$(podman mount $1)
-                  cp -r ${mnt}${2} $3
+                  cp -rT ${mnt}${2} $3
                   podman umount $1
                 }
             fi