Fix warnings

Author: mankinskin

egui/src/context_menu.rs

@@ -172,6 +172,7 @@ pub struct SubMenu {
     text: String,
 }
 impl SubMenu {
+    #[allow(clippy::needless_pass_by_value)]
     pub fn new(text: impl ToString) -> Self {
         Self {
             text: text.to_string(),

egui/src/response.rs

@@ -453,7 +453,7 @@ impl Response {
     }
 
     pub fn context_menu(&self, add_contents: impl FnOnce(&mut Ui, &mut super::context_menu::MenuState)) -> &Self {
-        self.ctx.show_context_menu(&self, add_contents);
+        self.ctx.show_context_menu(self, add_contents);
         self
     }
 }