Revert "tee mount & user namespace"

This reverts commit f7772db931001a49355bdf5659ad76d413bdc4bc.

Dockerfile

@@ -7,6 +7,4 @@ CMD set -x \
     && mkdir -p /prop-test/src /prop-test/vol/mp \
     && mount --bind /prop-test/src /prop-test/vol/mp \
     && date -Is | tee /prop-test/src/mount-timestamp \
-    && readlink /proc/self/ns/mnt | tee /prop-test/src/mntns \
-    && readlink /proc/self/ns/user | tee /prop-test/src/userns \
     && sleep 21m