sched/core: Fix CONFIG_GCC_PLUGIN_RANDSTRUCT build fail

As a temporary build fix, the proper cleanup needs more work.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Reported-by: NEric Biggers <ebiggers@kernel.org>
Suggested-by: NEric Biggers <ebiggers@kernel.org>
Suggested-by: NKees Cook <keescook@chromium.org>
Fixes: a1488664 ("sched: Replace rq::wake_list")
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

include/linux/sched.h

@@ -654,8 +654,10 @@ struct task_struct {
 	unsigned int			ptrace;
 
 #ifdef CONFIG_SMP
-	struct llist_node		wake_entry;
-	unsigned int			wake_entry_type;
+	struct {
+		struct llist_node		wake_entry;
+		unsigned int			wake_entry_type;
+	};
 	int				on_cpu;
 #ifdef CONFIG_THREAD_INFO_IN_TASK
 	/* Current CPU: */