fs: quota: use group allocation of per-cpu counters API

Use group allocation of per-cpu counters api to accelerate
dquot_init() and simplify code.

Signed-off-by: Kefeng Wang <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>
Message-Id: <[e-mail]>

fs/quota/dquot.c

···
 	if (!dquot_hash)
 		panic("Cannot create dquot hash table");
 
-	for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
-		ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL);
-		if (ret)
-			panic("Cannot create dquot stat counters");
-	}
+	ret = percpu_counter_init_many(dqstats.counter, 0, GFP_KERNEL,
+				       _DQST_DQSTAT_LAST);
+	if (ret)
+		panic("Cannot create dquot stat counters");
 
 	/* Find power-of-two hlist_heads which can fit into allocation */
 	nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);