f2fs: fix typo

Fix typo in f2fs.h
Detected by Jaeyoon Choi
Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -274,7 +274,7 @@ enum {
 	ORPHAN_INO,		/* for orphan ino list */
 	APPEND_INO,		/* for append ino list */
 	UPDATE_INO,		/* for update ino list */
-	TRANS_DIR_INO,		/* for trasactions dir ino list */
+	TRANS_DIR_INO,		/* for transactions dir ino list */
 	FLUSH_INO,		/* for multiple device flushing */
 	MAX_INO_ENTRY,		/* max. list */
 };