Format ui test files using rustfmt
diff --git a/tests/ui/empty_enum.stderr b/tests/ui/empty_enum.stderr
index c73578a..7f35019 100644
--- a/tests/ui/empty_enum.stderr
+++ b/tests/ui/empty_enum.stderr
@@ -1,7 +1,5 @@
 error: enums without any variants are not supported
  --> $DIR/empty_enum.rs:3:5
   |
-3 | /     enum A {
-4 | |
-5 | |     }
-  | |_____^
+3 |     enum A {}
+  |     ^^^^^^^^^