audit: don't reset working wait time accidentally with auditd

During a queue overflow condition while we are waiting for auditd to drain the
queue to make room for regular messages, we don't want a successful auditd that
has bypassed the queue check to reset the backlog wait time.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>