workqueue: use %*pb[l] to format bitmaps including cpumasks and nodemasks

printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/workqueue.c

@@ -3083,10 +3083,9 @@ static ssize_t wq_cpumask_show(struct device *dev,
 	int written;
 
 	mutex_lock(&wq->mutex);
-	written = cpumask_scnprintf(buf, PAGE_SIZE, wq->unbound_attrs->cpumask);
+	written = scnprintf(buf, PAGE_SIZE, "%*pb\n",
+			    cpumask_pr_args(wq->unbound_attrs->cpumask));
 	mutex_unlock(&wq->mutex);
-
-	written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
 	return written;
 }