f2fs: check hot_data for roll-forward recovery

commit 125c9fb1 upstream.

We need to check HOT_DATA to truncate any previous data block when doing
roll-forward recovery.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>