Fix clippy issues.

src/main.rs

@@ -18,10 +18,7 @@ mod render;
 
 fn main() -> Result<ExitCode, CustomError> {
     let rt = tokio::runtime::Runtime::new()?;
-    rt.block_on(async {
-        let main_body_result = main_body().await;
-        main_body_result
-    })
+    rt.block_on(async { main_body().await })
 }
 
 async fn main_body() -> Result<ExitCode, CustomError> {