Use rustfmt::skip (bad formatting is required to trigger the bug)

Author: sanxiyn

tests/ui/unnecessary_operation.fixed

@@ -108,6 +108,8 @@ fn main() {
     Cout << 16;
 
     // Issue #11575
+    // Bad formatting is required to trigger the bug
+    #[rustfmt::skip]
     'label: {
         break 'label
     };

tests/ui/unnecessary_operation.rs

@@ -112,6 +112,8 @@ fn main() {
     Cout << 16;
 
     // Issue #11575
+    // Bad formatting is required to trigger the bug
+    #[rustfmt::skip]
     'label: {
         break 'label
     };