configfs: return -ENAMETOOLONG earlier in configfs_lookup

Just like most other file systems: get the simple checks out of the
way first.
Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/configfs/dir.c

@@ -456,6 +456,9 @@ static struct dentry * configfs_lookup(struct inode *dir,
 	int found = 0;
 	int err;
 
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
 	/*
 	 * Fake invisibility if dir belongs to a group/default groups hierarchy
 	 * being attached
@@ -486,8 +489,6 @@ static struct dentry * configfs_lookup(struct inode *dir,
 		 * If it doesn't exist and it isn't a NOT_PINNED item,
 		 * it must be negative.
 		 */
-		if (dentry->d_name.len > NAME_MAX)
-			return ERR_PTR(-ENAMETOOLONG);
 		d_add(dentry, NULL);
 		return NULL;
 	}