fsck.f2fs: fix double free invalid checkpoint

The invalid checkpoin is freed in validate_checkpoint().

Change-Id: I9025683078e7c2c99695d8f098aef9864e215c67
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed