mkfs.f2fs: treat db's data as hot one

DB files like .db, .db-journal, .db-wal, .db-shm are very active, this
patch adds db file type to hot file extension list by default.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed