audit: check audit_enabled in audit_tree_log_remove_rule()

Respect the audit_enabled flag when printing tree rule config change
records.

See: https://github.com/linux-audit/audit-kernel/issues/50



Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: tweak the subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>