[clang] [CIR] Simplify error emission to return failures directly (PR #141032)

[Henrich Lauko via cfe-commits]

xlauko wrote:

### Merge activity

* **May 22, 4:51 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/141032).


https://github.com/llvm/llvm-project/pull/141032