btrfs: typo: 'btrfS' -> 'btrfs'

Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/dir-item.c

@@ -452,7 +452,7 @@ int verify_dir_item(struct btrfs_root *root,
 		namelen = XATTR_NAME_MAX;
 
 	if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
-		printk(KERN_CRIT "btrfS: invalid dir item name len: %u\n",
+		printk(KERN_CRIT "btrfs: invalid dir item name len: %u\n",
 		       (unsigned)btrfs_dir_data_len(leaf, dir_item));
 		return 1;
 	}