[clang-tools-extra] [clang-tidy] Fix crash in modernize-use-designated-initializers check (PR #113688)

[Nicolas van Kempen via cfe-commits]

https://github.com/nicovank approved this pull request.

Looking at it again, this way is also good, no preference. Good to merge 👍 

https://github.com/llvm/llvm-project/pull/113688