f2fs: update file name in the inode block during f2fs_rename

The error is reproducible by:
0. mkfs.f2fs /dev/sdb1 & mount
1. touch test1
2. touch test2
3. mv test1 test2
4. umount
5. dumpt.f2fs -i 4 /dev/sdb1

After this, when we retrieve the inode->i_name of test2 by dump.f2fs, we get
test1 instead of test2.
This is because f2fs didn't update the file name during the f2fs_rename.

So, this patch fixes that.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 64c0716..3297278 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -427,6 +427,11 @@
 		if (!new_entry)
 			goto out_dir;
 
+		if (update_dent_inode(old_inode, &new_dentry->d_name)) {
+			f2fs_put_page(new_page, 1);
+			goto out_dir;
+		}
+
 		f2fs_set_link(new_dir, new_entry, new_page, old_inode);
 
 		new_inode->i_ctime = CURRENT_TIME;