Fix dead code warning in issue 795 regression test
Fix dead code warning in issue 795 regression test

    warning: field is never read: `x`
     --> tests/regression/issue795.rs:9:15
      |
    9 |     Variant { x: u8 },
      |               ^^^^^
      |
      = note: `#[warn(dead_code)]` on by default

serde-rs/json,google/serde_json_lenient