[clang] [Clang][AST][NFC] Correct Comment in GenericSelectionExpr (PR #180850)

[Will Hawkins via cfe-commits]

hawkinsw wrote:

> LGTM, thank you for the comment cleanup!

Thank you _so_ much for the feedback. I am still _relatively_ new to LLVM -- now that you have approved the commit (and I rebase on main), is it okay for me to merge? 

I am so sorry for having to bother you with these silly details, but I just don't want to do something wrong.

Thank you again for allowing me to participate! 

https://github.com/llvm/llvm-project/pull/180850