[clang] [clang][StaticAnalyzer] fix function evalCall() typo in CheckerDocumentation (PR #83677)

[Balazs Benics via cfe-commits]

steakhal wrote:

Makes sense, but how did it build before the fix?
I thought by inheriting from `Checker` it would take the address of the member function with the expected signature to store them inside vectors. How could it take the address of a nonexisting member function?

https://github.com/llvm/llvm-project/pull/83677