[clang] [llvm] Add parentheses to clarify operator ordering in asserts. NFC. (PR #159333)

[David Spickett via llvm-commits]

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

ISTR some rule about not using more brackets than are needed but it could have been project specific.

But even if that exists, https://llvm.org/docs/CodingStandards.html#treat-compiler-warnings-like-errors tells us to fix compiler warnings so let's fix it.

LGTM.

https://github.com/llvm/llvm-project/pull/159333