[llvm] [AArch64] Add an early return and de-indent a long indented block (NFC) (PR #201345)

[Ömer Sinan Ağacan via llvm-commits]

osa1 wrote:

Thanks for the review. I agree that it's not great that pollute `git blame` output with this kind of thing, but it may also not be too difficult to skip NFCs in `git blame` output. For example:

```
git blame $(git log --grep='(NFC)' --pretty=format:'--ignore-rev %H ' -- test.txt) -- test.txt
```

This passes `--ignore-rev` flags to `git blame` with commits that contain '(NFC)' in the message.

(I have no idea how to do the same in my IDE though..)

The reason why I made this change is I'm working on this file (will be creating another PR in a few days hopefully), and I think this change makes it much easier to follow the control flow in this function.

https://github.com/llvm/llvm-project/pull/201345