workqueue: Change the code of calculating work_flags in insert_wq_barrier()

Add a local var @work_flags to calculate work_flags step by step, so that
we don't need to squeeze several flags in only the last line of code.

Parepare for next patch to add a bit to barrier work item's flag.  Not
squshing this to next patch makes it clear that what it will have changed.

No functional change intended.
Signed-off-by: NLai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

kernel/workqueue.c

@@ -2659,8 +2659,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq,
 			      struct wq_barrier *barr,
 			      struct work_struct *target, struct worker *worker)
 {
+	unsigned int work_flags = work_color_to_flags(WORK_NO_COLOR);
 	struct list_head *head;
-	unsigned int linked = 0;
 
 	/*
 	 * debugobject calls are safe here even with pool->lock locked
@@ -2686,13 +2686,12 @@ static void insert_wq_barrier(struct pool_workqueue *pwq,
 
 		head = target->entry.next;
 		/* there can already be other linked works, inherit and set */
-		linked = *bits & WORK_STRUCT_LINKED;
+		work_flags |= *bits & WORK_STRUCT_LINKED;
 		__set_bit(WORK_STRUCT_LINKED_BIT, bits);
 	}
 
 	debug_work_activate(&barr->work);
-	insert_work(pwq, &barr->work, head,
-		    work_color_to_flags(WORK_NO_COLOR) | linked);
+	insert_work(pwq, &barr->work, head, work_flags);
 }
 
 /**