Fix new lint warning in clippy_config

Author: GuillaumeGomez

clippy_config/src/conf.rs

@@ -173,7 +173,9 @@ macro_rules! define_Conf {
                             }
                         })*
                         // ignore contents of the third_party key
-                        Ok(Field::third_party) => drop(map.next_value::<IgnoredAny>())
+                        Ok(Field::third_party) => {
+                            let _ = map.next_value::<IgnoredAny>();
+                        }
                     }
                 }
                 let conf = Conf { $($name: $name.unwrap_or_else(defaults::$name),)* };

clippy_dev/src/update_lints.rs

@@ -999,7 +999,7 @@ fn try_rename_file(old_name: &Path, new_name: &Path) -> bool {
     match fs::rename(old_name, new_name) {
         Ok(()) => true,
         Err(e) => {
-            drop(fs::remove_file(new_name));
+            let _ = fs::remove_file(new_name);
             if e.kind() == io::ErrorKind::NotFound {
                 false
             } else {

tests/ui/drop_result.rs

@@ -1,4 +1,4 @@
-#[warn(clippy::drop_result)]
+#![warn(clippy::drop_result)]
 
 fn make_result<T>(t: T) -> Result<T, ()> {
     Ok(t)

tests/ui/drop_result.stderr

@@ -1,5 +1,5 @@
 error: using `drop()` on a `Result` type
-  --> $DIR/drop_result.rs:6:5
+  --> $DIR/drop_result.rs:8:5
    |
 LL |     drop(Ok::<String, ()>("a".to_string()));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -8,13 +8,13 @@ LL |     drop(Ok::<String, ()>("a".to_string()));
    = help: to override `-D warnings` add `#[allow(clippy::drop_result)]`
 
 error: using `drop()` on a `Result` type
-  --> $DIR/drop_result.rs:8:5
+  --> $DIR/drop_result.rs:10:5
    |
 LL |     drop(x);
    |     ^^^^^^^
 
 error: using `drop()` on a `Result` type
-  --> $DIR/drop_result.rs:9:5
+  --> $DIR/drop_result.rs:11:5
    |
 LL |     drop(make_result("a".to_string()));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^