Fix a clippy "unnecessary closure" warning

Clippy 1.59 beta says:

error: unnecessary closure used to substitute value for `Option::None`
   --> src/properties.rs:119:22
    |
119 |           let offset = reply
    |  ______________________^
120 | |             .value
121 | |             .iter()
122 | |             .position(|&v| v == 0)
123 | |             .unwrap_or_else(|| reply.value.len());
    | |_________________________________________________^
    |
    = note: `-D clippy::unnecessary-lazy-evaluations` implied by `-D warnings`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations
help: use `unwrap_or` instead
    |
119 ~         let offset = reply
120 +             .value
121 +             .iter()
122 ~             .position(|&v| v == 0).unwrap_or(reply.value.len());
    |

Signed-off-by: Uli Schlachter <[email protected]>

src/properties.rs

@@ -120,7 +120,7 @@ impl WmClass {
             .value
             .iter()
             .position(|&v| v == 0)
-            .unwrap_or_else(|| reply.value.len());
+            .unwrap_or(reply.value.len());
         Ok(WmClass(reply, offset))
     }