wrong_self_convention: fix dogfood test

There was a `single-match-else` clippy warning.

Author: mgacek8

clippy_lints/src/methods/mod.rs

@@ -1968,17 +1968,17 @@ fn lint_wrong_self_convention<'tcx>(
                             None
                         }
                     };
-                    match special_case {
-                        Some(suggestion) => suggestion,
-                        None => {
-                            let s = conventions
-                                .iter()
-                                .map(|c| format!("`{}`", &c.to_string()))
-                                .collect::<Vec<_>>()
-                                .join(" and ");
-
-                            format!("methods called like this: ({})", &s)
-                        },
+
+                    if let Some(suggestion) = special_case {
+                        suggestion
+                    } else {
+                        let s = conventions
+                            .iter()
+                            .map(|c| format!("`{}`", &c.to_string()))
+                            .collect::<Vec<_>>()
+                            .join(" and ");
+
+                        format!("methods called like this: ({})", &s)
                     }
                 } else {
                     format!("methods called `{}`", &conventions[0])