Only disable formatting for CHECK directives

Author: Alexander Batashev

sycl/test/abi/layout_handler.cpp

@@ -1,8 +1,6 @@
 // RUN: %clangxx -fsycl -c -fno-color-diagnostics -Xclang -fdump-record-layouts %s | FileCheck %s
 // REQUIRES: linux
 
-// clang-format off
-
 #include <CL/sycl/handler.hpp>
 #include <CL/sycl/queue.hpp>
 
@@ -13,6 +11,8 @@ void foo() {
   });
 }
 
+// clang-format off
+
 // The order of field declarations and their types are important.
 
 // CHECK: 0 | class sycl::handler