filesystem: minor fix (#1557)

Minor fix, I'm guessing this was the original intention.

filesystem/05-home-dir.post

@@ -252,8 +252,8 @@ maybe_create_home ()
   # CHERE_INVOKING=1; exec /usr/bin/bash --login -i"
   # 
   # Make sure we start in home if invoked without -here option and not in a nested shell
-  if [ ! -z "${CHERE_INVOKING}" ]; then
-    CHERE_INVOKING_VISIBLE_FOR_USER=CHERE_INVOKING
+  if [ -n "${CHERE_INVOKING}" ]; then
+    CHERE_INVOKING_VISIBLE_FOR_USER="${CHERE_INVOKING}"
     unset CHERE_INVOKING
   elif [ ${SHLVL:-0} -le 1 ]; then
     cd "${HOME}" || echo "WARNING: Failed attempt to cd into ${HOME}!"