[clang-tidy] fix duplicate '{}' in cppcoreguidelines-pro-type-member-init

The overload of the constructor will repeatedly fix the member variables that need to be initialized.
Removed the duplicate '{}'.

```
struct A {
  A() {}
  A(int) {}
  int _var;  // int _var{}{};  <--  wrong fix
};
```

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D107641