f2fs: release new entry page correctly in error path of f2fs_rename

This patch correct releasing code of new_page to avoid BUG_ON in error patch of
f2fs_rename.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/namei.c

@@ -474,7 +474,8 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	return 0;
 
 put_out_dir:
-	f2fs_put_page(new_page, 1);
+	kunmap(new_page);
+	f2fs_put_page(new_page, 0);
 out_dir:
 	if (old_dir_entry) {
 		kunmap(old_dir_page);