ticdc: some typo about Changefeed

[wk989898]

What did you do?

Some Changefeed are wrong writing. For example: https://github.com/pingcap/tiflow/blob/566c77cab9dfc758767a035f3dab0d3a5c3c2788/cdc/owner/feed_state.go#L29

What did you expect to see?

No response

What did you see instead?

correct writing: Changefeed

Versions of the cluster

master

[fubinzh]

/severity minor