[clang] [NFC][Clang] Fix static analyzer bugs with dereference after null checks (PR #86018)

[Eli Friedman via cfe-commits]

https://github.com/efriedma-quic requested changes to this pull request.

If you read the code, it should be obvious the pointer is in fact non-null.  Please don't insert null checks into the code just to address static analyzer false positives.

https://github.com/llvm/llvm-project/pull/86018