Clean up E0071 long explanation

Author: GuillaumeGomez

src/librustc_error_codes/error_codes/E0071.md

@@ -1,5 +1,5 @@
-You tried to use structure-literal syntax to create an item that is
-not a structure or enum variant.
+A structure-literal syntax was used to create an item that is not a structure
+or enum variant.
 
 Example of erroneous code:
 
@@ -9,8 +9,8 @@ let t = U32 { value: 4 }; // error: expected struct, variant or union type,
                           // found builtin type `u32`
 ```
 
-To fix this, ensure that the name was correctly spelled, and that
-the correct form of initializer was used.
+To fix this, ensure that the name was correctly spelled, and that the correct
+form of initializer was used.
 
 For example, the code above can be fixed to: