Fix grammar and tense in API coexistence explanation

[I-Ying-Tsai]

The original sentence was ungrammatical and slightly unclear.
This patch improves the article usage, verb tense, and phrasing
to ensure clarity and correctness.

Summary by Bito

This pull request enhances the clarity and grammatical correctness of the API coexistence documentation in the Linux kernel. It improves phrasing and verb tense for better understanding, making the documentation more precise and easier to read.

[visitorckw]

Original: "One of the reasons why API was changed is it need to coexist with the old version interface."

Issues:

• Missing article ("the API")
• Verb tense disagreement ("it need" → "it needed")
• Unnatural phrase ("old version interface")

Revised: "One of the reasons why the API was changed is that it needed to coexist with the old version of the interface."

You don't need to include the full "Original" and "Revised" texts in the changelog. The git diff already shows the specific changes. Instead, please focus the changelog on why the change is necessary, rather than detailing exactly what was changed.

[I-Ying-Tsai]

Thank you! I've updated the commit accordingly

[jserv]

Read https://cbea.ms/git-commit/ carefully and enforce the rules.

[I-Ying-Tsai]

Sorry for forgetting this. I've updated the commit message and PR description accordingly. Thank you!

[visitorckw]

I saw that you updated the PR description, but the commit message in the git history hasn't been updated yet.

[I-Ying-Tsai]

Commit message has been updated to follow project and community guidelines. Thanks for the reminder!

[jserv]

Thank @I-Ying-Tsai for contributing!