add comment for ext4_dir_entry_2 file_type member

Signed-off-by: Jonathan Grant <jg@jguk.org>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/ad3290d5-86af-99c1-f9d5-cd1bab710429@jguk.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ext4.h

@@ -2061,7 +2061,7 @@ struct ext4_dir_entry_2 {
 	__le32	inode;			/* Inode number */
 	__le16	rec_len;		/* Directory entry length */
 	__u8	name_len;		/* Name length */
-	__u8	file_type;
+	__u8	file_type;		/* See file type macros EXT4_FT_* below */
 	char	name[EXT4_NAME_LEN];	/* File name */
 };