trimming task_work: kill ->data

get rid of the only user of ->data; this is _not_ the final variant - in the
end we'll have task_work and rcu_head identical and just use cred->rcu,
at which point the separate allocation will be gone completely.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/task_work.h b/include/linux/task_work.h
index 294d5d5..627421c 100644
--- a/include/linux/task_work.h
+++ b/include/linux/task_work.h
@@ -10,14 +10,12 @@
 struct task_work {
 	struct hlist_node hlist;
 	task_work_func_t func;
-	void *data;
 };
 
 static inline void
-init_task_work(struct task_work *twork, task_work_func_t func, void *data)
+init_task_work(struct task_work *twork, task_work_func_t func)
 {
 	twork->func = func;
-	twork->data = data;
 }
 
 int task_work_add(struct task_struct *task, struct task_work *twork, bool);