irq/work: Don't reinvent the wheel but use existing llist API

Use the proper llist APIs instead of open-coded variants of them.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1509414414-14987-1-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/irq_work.c

@@ -138,11 +138,7 @@ static void irq_work_run_list(struct llist_head *list)
 		return;
 
 	llnode = llist_del_all(list);
-	while (llnode != NULL) {
+	llist_for_each_entry(work, llnode, llnode) {
-		work = llist_entry(llnode, struct irq_work, llnode);
-
-		llnode = llist_next(llnode);
-
 		/*
 		 * Clear the PENDING bit, after this point the @work
 		 * can be re-used.