container-puppet.sh: add -r to rm command

When purging config files, it can happen that we try to remove a
directory. Example for the ironic_pxe container:

  rm: cannot remove ‘/var/lib/config-data/puppet-generated/ironic/etc/my.cnf.d/’: Is a directory

So just add -r to the rm command, so the purge can finish.

Depends-On: https://review.opendev.org/#/c/705757/
Change-Id: Ib821cfc95e4349b681c08ac86ad97b742c933983

common/container-puppet.sh

@@ -121,7 +121,7 @@ if [ -z "$NO_ARCHIVE" ]; then
     echo "Ensuring the removed config files are also purged in ${puppet_generated_path}:"
     cat $TMPFILE | sort
     cat $TMPFILE | xargs -n1 -r -I{} \
-        bash -c "rm -f ${puppet_generated_path}/{}"
+        bash -c "rm -rf ${puppet_generated_path}/{}"
     exec 5>&1
     exec 1>$TMPFILE2
     find $rsync_srcs -newer $origin_of_time -not -path '/etc/puppet*' -print0