fix some nit issue, typo, refactor

[googs1025]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

• fix some typo
• reduce duplicate code and increase code reuse
• refactor some judgment statements to increase code readability

  Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?

None

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

None

[NickrenREN]

LGTM, @XinyiSong @binacs PTAL