cppcheck: fix broken hash

The original hash is for https://github.com/danmar/cppcheck/commit/4a17dcb and the new hash is for https://github.com/danmar/cppcheck/commit/ef1c70f.

pkgs/development/tools/analysis/cppcheck/default.nix

···
     owner = "danmar";
     repo = "cppcheck";
     rev = version;
-    sha256 = "sha256-8vwuNK7qQg+pkUnWpEe8272BuHJUaidm8MoGsXVt1X8=";
+    hash = "sha256-bKZOAGInks26NmzlKo1T8NREO9xoF8ZsssNDzyTJwlU=";
   };
 
   buildInputs = [ pcre