Remove useless spaces

Author: GuillaumeGomez

src/librustc/diagnostics.rs

@@ -195,7 +195,7 @@ impl ::std::ops::Index<u8> for Foo {
 }
 
 const a: Foo = Foo { a: 0u8};
-const b: u8 = a[0]; // Index trait is defined by the user, bad !
+const b: u8 = a[0]; // Index trait is defined by the user, bad!
 ```
 
 The only traits which can be used have to be already implemented, not user-defined.
@@ -204,7 +204,7 @@ Example :
 
 ```
 const a: &'static [i32] = &[1, 2, 3];
-const b: i32 = a[0]; // Good !
+const b: i32 = a[0]; // Good!
 ```
 "##,