Description of problem:
upgrade from 4.4 to 4.5, fluentd expr: division by zero.

$oc logs fluentd-lgnhd
expr: division by zero
run.sh: line 103: [: too many arguments
expr: syntax error
run.sh: line 108: [: too many arguments

Version-Release number of selected component (if applicable):
4.4->4.5

How reproducible:
Always

Steps to Reproduce:
1. Install clusterlogging.4.4.0-202005180840.
2. Enable TechPreview Logforward.

kind: LogForwarding
metadata:   
  name: instance   
  namespace: openshift-logging
spec:   
  outputs:     
    - name: elasticsearch-default
      type: elasticsearch
      endpoint: 'elasticsearch.openshift-logging.svc:9200'
      secret:
         name: 'fluentd'
    - name: fluentd-created-by-user
      type: forward
      endpoint: 'fluentdserver.openshift-logging.svc:24224'
      secret:
         name: 'fluentdserver'
  pipelines:
    - name: app-pipeline
      inputSource: logs.app
      outputRefs:
        - elasticsearch-default
    - name: infra-pipeline
      inputSource: logs.infra
      outputRefs:
        - fluentd-created-by-user
    - name: audit-pipeline
      inputSource: logs.audit
      outputRefs:
        - fluentd-created-by-user


3. Enable Configmap syslog forward
 <store>
     @type syslog
     remote_syslog 172.30.66.248
     port 514
     hostname $hostname
     remove_tag_prefix tag
     tag_key ident,systemd.u.SYSLOG_IDENTIFIER
     facility local0
     severity info
     use_record true
     payload_key message
    </store>
4. Upgrade to 4.5.

Actual results:
expr: division by zero. Please refer to the attached ConfigMap and fluent debug Log

Expected results:


Additional info: