[BUG] SidecarSet maxunvailable=5% and matched pods = 6, but upgrade block.

[zmberg]

What happened:
I1104 09:45:44.530512 1 sidecarset_controller.go:93] Observed updated Spec for SidecarSet: /clickhouse-exporter
I1104 09:45:44.530582 1 sidecarset_controller.go:141] begin to process sidecarset clickhouse-exporter for reconcile
I1104 09:45:44.548081 1 sidecarset_processor.go:270] sidecarSet(clickhouse-exporter) update status(MatchedPods:6, UpdatedPods:0, ReadyPods:6, UpdatedReadyPods:0) success
I1104 09:45:44.548324 1 sidecarset_strategy.go:85] sidecarSet(clickhouse-exporter) matchedPods(6) waitUpdated(6) notUpgradable(0)
I1104 09:45:44.548388 1 sidecarset_processor.go:174] sidecarSet next update is nil, skip this round, name: clickhouse-exporter

  updateStrategy:
    maxUnavailable: 5%
    partition: 0
    type: RollingUpdate
status:
  collisionCount: 0
  latestRevision: xxxxx-f4686f8b6
  matchedPods: 6
  observedGeneration: 4
  readyPods: 6
  updatedPods: 0
  updatedReadyPods: 0

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Kruise version: 1.5.x
• Kubernetes version (use kubectl version):
• Install details (e.g. helm install args):
• Others: