quota: use lockdep_assert_held_write in dquot_load_quota_sb

Use lockdep_assert_held_write to assert and self-document the locking
state in dquot_load_quota_sb instead of hand-crafting it with a trylock.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230802115439.2145212-2-hch@lst.de>

fs/quota/dquot.c

@@ -2365,11 +2365,10 @@ int dquot_load_quota_sb(struct super_block *sb, int type, int format_id,
 	struct quota_info *dqopt = sb_dqopt(sb);
 	int error;
 
+	lockdep_assert_held_write(&sb->s_umount);
+
 	/* Just unsuspend quotas? */
 	BUG_ON(flags & DQUOT_SUSPENDED);
-	/* s_umount should be held in exclusive mode */
-	if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
-		up_read(&sb->s_umount);
 
 	if (!fmt)
 		return -ESRCH;