Bad varid for enumerator with using namespace

[chrchr]

From #14952:

namespace O {}
namespace N {
        using namespace O;
        enum class E { E0 };
        auto E0 = E::E0;        
}

2: namespace N {
3: using namespace O ;
4: enum class E { E0@var1 } ;
5: auto E0@var1 ; E0@var1 =@exprUNIQUE E ::@exprUNIQUE E0@var1 ;
6: }

[ludviggunne]

Fixed by ​https://github.com/cppcheck-opensource/cppcheck/pull/8773.