fsck.f2fs: fix corrupted nat entry [0]

The first nat entry must be null. If it is corrupted, we set its bit in
nat_area_bitmap, without increasing valid_nat_entry_cnt, fsck_verify will
nullify it at last.

Reported-by: Cheng Yinchao <chengyinchao@huawei.com>
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed