Fix tidy formatting manually for E0423.md

compiler/rustc_error_codes/src/error_codes/E0423.md

@@ -45,15 +45,13 @@ fn h1() -> i32 {
 }
 ```
 
-
-
 ### Enum types used as values
 
 Enums are types and cannot be used directly as values.
 
 ```compile_fail,E0423
-fn main() {
+fn main(){
     let x = Option::<i32>;
-    //~^ ERROR expected value, found enum `Option`
+    //~^ ERROR expected value,found enum `Option`
 }
-```
+```