Fix whitespace

Author: nikomatsakis

src/test/compile-fail/issue-7092.rs

@@ -18,7 +18,7 @@ fn foo(x: Whatever) {
 //~| expected type `Whatever`
 //~| found type `std::option::Option<_>`
 //~| expected enum `Whatever`, found enum `std::option::Option`
-            field.access(), 
+            field.access(),
     }
 }